fix(fleet): harden #791 upgrade rollback against find/reset failures

Second- and third-round independent-review reliability fixes on the keep-mode
upgrade rollback path, plus accurate abort messaging. All fixed red-first with
self-verifying controls in the rollback gate.

Round 2 (blockers A/B, should-fix C):
- install.sh: `trap 'restore_snapshot; exit 1' ERR INT TERM` so an INT/TERM
  mid-sync terminates instead of resuming past the interrupt and reporting
  success (a bash signal handler that only returns does not terminate).
- manifest.{ts,sh}: reject a degenerate [framework] section whose entries are
  all empty or bare-dot (`/`, `./`, `.`, `..`) — it passed the non-empty guard
  yet yielded zero usable globs, silently resolving everything to operator.
  Parity via a shared `[^/.]` usable-glob test; TS throws ManifestError.
- finalize.ts: classify the sync-abort message — a ManifestError is a pre-sync
  validation abort ("no files were changed"); any other error may be partial.

Round 3 (blockers D1, D2):
- install.sh: enumerate framework files with a checked temp file (_scan_or_die)
  instead of `< <(find …)` — process substitution discards find's exit status,
  so an EACCES/I/O failure mid-scan would truncate the file list yet leave the
  loop exiting 0, committing a partial upgrade as success (ERR trap never fires).
- install.sh: guard the `rm -rf; mkdir -p` target reset inside restore_snapshot
  — a bare reset failing under set -e exits silently after partial deletion,
  never printing the snapshot-recovery pointer. Now checked like the cp -a
  restore: on failure it preserves the snapshot and tells the operator where.

Tests: rollback gate 14→28 (Parts C/D/E with disabled-guard controls);
new finalize-sync-abort.spec.ts (3). No secret value is ever emitted; snapshots
stay 0700. Gates green: typecheck, lint, format:check, full mosaic vitest 1094,
HARD GATE 193, rollback 28, migration 21.

Refs #791

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.woodpecker/ci.yml

@@ -44,14 +44,19 @@ steps:
 
   # Blocking gate (#791): a framework upgrade must never write or delete an
   # operator-owned path. The HARD GATE proves an unanticipated operator sentinel
-  # survives a keep-mode reseed byte-identical (both rsync + cp paths); the
-  # migration matrix pins the v2→v3 contract-file semantics. Pure bash, no
-  # node_modules — runs early alongside sanitization.
+  # survives a keep-mode reseed byte-identical (with rsync present AND absent —
+  # keep mode is a single cp-based path that must not depend on rsync), and that a
+  # corrupt/empty/missing manifest aborts fail-closed leaving operator files
+  # untouched (B2/B3). The rollback gate proves a mid-sync failure is rolled back
+  # from the pre-update snapshot (B1). The migration matrix pins the v2→v3
+  # contract-file semantics. Pure bash, no node_modules — runs early alongside
+  # sanitization.
   upgrade-guard:
     image: *node_image
     commands:
       - apk add --no-cache bash rsync
       - bash packages/mosaic/framework/tools/quality/scripts/test-upgrade-manifest-guard.sh
+      - bash packages/mosaic/framework/tools/quality/scripts/test-upgrade-rollback.sh
       - bash packages/mosaic/framework/tools/quality/scripts/test-install-migration.sh
 
   typecheck:

docs/scratchpads/791-upgrade-config-protection.md

@@ -123,3 +123,94 @@ must survive upgrade. Two coupled deliverables landed in PR1:
   WITH the carve-out → deny-wins → operator, unprunable (GREEN). manifest.spec.ts 21/21 (was 18).
 - Gates all green: typecheck ✓ lint ✓ format:check ✓ · full mosaic vitest 1069 passed · HARD GATE 58/58
   · migration 21/21. Committing FORWARD on the branch (NOT rebasing 34e55d4a out from under review).
+
+### MS-LEAD REQUEST CHANGES @ 0a5e703a → B1/B2/B3 fixed red-first (2026-07-16)
+MS-LEAD returned REQUEST CHANGES (routed merge-blockers satisfied; 2 CRITICAL reliability defects from
+the commissioned independent review). Fixed forward on the branch, red-first:
+- **B1 (CRITICAL) — dead ERR trap.** install.sh had `set -euo pipefail` (no `-E`), so the
+  `trap restore_snapshot ERR` never fired for a failure inside sync_framework_keep() (function body) —
+  a mid-sync abort left a half-written target with NO rollback. Fix: `set -Eeuo pipefail` (errtrace) +
+  disarm the trap at the top of restore_snapshot() to prevent re-entrancy. New gate
+  `test-upgrade-rollback.sh`: injects a mid-sync `cp` EACCES (read-only divergent framework file);
+  Part A asserts the shipped installer rolls back (restore message fires AND target byte-identical to
+  pre-upgrade); Part B control strips `-E` and asserts the rollback message does NOT fire (dead trap) —
+  self-verifying red→green. 7/7.
+- **B2/B3 (CRITICAL) — empty/unreadable/malformed manifest divergence.** Pre-fix: TS `parseManifest('')`
+  returned `{framework:[],operator:[]}` (NO throw) → silent no-op "Installation complete"; bash aborted
+  fragilely (the `_manifest_compile` `"${MANIFEST_OPERATOR[@]:-}"` artifact returned 1 with no message)
+  AND the CLI dispatch swallowed manifest_load's rc (no `|| exit`) so `resolve` exited 0 resolving
+  everything operator. Fix (fail-loud + identical both langs):
+  * TS `parseManifest`: throw on zero framework entries; `loadManifest`: wrap read error →
+    "Cannot read framework manifest …".
+  * bash `manifest_load`: explicit unreadable guard (`[[ ! -r ]]`) + zero-`[framework]` guard, both loud
+    stderr + return 1; `_manifest_compile` gets explicit `return 0` (kills the empty-array artifact);
+    CLI dispatch `manifest_load … || exit 1`.
+  * `finalize.ts`: wrap syncFramework → `spin.stop('Framework sync aborted …')` + rethrow (never falls
+    through to "Installation complete").
+  Tests: manifest.spec.ts +5 fail-closed (empty/comment-only/operator-only/empty-section/missing);
+  manifest-parity.spec.ts +7 failure-mode parity (both reject empty/comment-only/operator-only/
+  empty-section/entry-before-header/unknown-header/missing — TS throws, bash CLI exits non-zero+stderr);
+  HARD GATE +4 end-to-end fail-closed matrices (empty/operator-only/malformed/missing → abort non-zero,
+  manifest error surfaced, every operator sentinel byte-identical). RED proven by reverting
+  manifest.ts+manifest.sh to HEAD → 12 new tests fail; restore → 40/40 green.
+- **Non-blocking addressed.** MEDIUM install.sh:222 find-empty now warns on a real failure instead of
+  blanket `|| true`. LOW: corrected the "both destructive paths rsync vs cp" overstatement in the HARD
+  GATE header + cp-fallback comment + ci.yml (keep mode is a single cp-based path; the rsync-present vs
+  -absent runs prove rsync-independence). `.pre-constitution.bak` triage: single-shot backup is
+  intentional (reconcile_framework_files backs up once), no change.
+- Gates: typecheck ✓ lint ✓ format:check ✓ · full mosaic vitest 1081 passed (was 1069, +12) · HARD GATE
+  118/118 (was 58) · rollback 7/7 (new) · migration 21/21. No --no-verify. Rollback test wired into
+  ci.yml upgrade-guard. Committing FORWARD (no rebase of 34e55d4a/0a5e703a).
+
+### Codex round 2 (pre-push self-review) → blockers A/B + should-fix C fixed red-first (2026-07-16)
+Before committing round 1 I re-ran codex on the change set; it surfaced two fresh reliability defects
+and one messaging defect on the SAME rollback/manifest path. Fixed forward, red-first:
+- **Blocker-A (CRITICAL) — signal trap resumed instead of terminating.** A bash INT/TERM handler that
+  merely `restore_snapshot` (returns) does NOT terminate the script — execution RESUMES past the
+  interrupt, cleans the snapshot and reports success, leaving a partial post-interrupt update. Fix:
+  `trap 'restore_snapshot; exit 1' ERR INT TERM` so both the errtrace (ERR) and signal (INT/TERM) paths
+  exit non-zero. Rollback test Part C: a `cp` shim that `kill -TERM $PPID` mid-sync then succeeds (so
+  set -e never fires and only the signal path governs) → asserts abort non-zero + restore fires + does
+  NOT print "file phase complete"; control strips `exit 1` and asserts the buggy resume-to-success.
+- **Blocker-B (CRITICAL) — degenerate `[framework]` section resolved everything operator.** A manifest
+  whose framework entries are all empty / bare-dot (`/`, `./`, `.`, `..`) passed the non-empty guard yet
+  yielded zero usable globs → nothing is framework → a keep-mode sync silently no-ops (bash resolved
+  `operator`, exit 0). Fix (both langs, parity): reject when no entry has a char other than `/`/`.` —
+  TS `isUsableFrameworkGlob` = `/[^/.]/.test(normalizeRel(glob))`, throws `ManifestError`; bash mirror
+  loops `[[ "$(_manifest_norm "$_g")" =~ [^/.] ]]`, loud stderr + return 1. Tests: manifest.spec.ts
+  `it.each(['/','./','.','..','/\n./'])` throw; parity +3 `expectBothReject` (root-slash/dot-slash/
+  bare-dot). RED: reverting the guard makes `[framework]\n/` resolve `operator` exit 0.
+- **Should-fix-C — misleading abort message.** finalize.ts printed one generic "may be partially
+  applied" for every sync failure. A `ManifestError` is a PRE-sync validation abort (manifest is
+  validated before any copy) → nothing was written; conflating it with a mid-copy failure misdirects
+  recovery. Fix: introduce `ManifestError` (exported from manifest.ts, thrown by every fail-closed
+  parse/load path), and classify in finalize.ts — ManifestError → "no files were changed"; any other →
+  "may be partially applied". New co-located `finalize-sync-abort.spec.ts` (3 tests) asserts both
+  branches re-throw the original error + the correct message, and that config writes are never reached.
+  RED proven by collapsing the classification → the ManifestError test fails.
+- Gates: typecheck ✓ lint ✓ format:check ✓ · full mosaic vitest 1094 (was 1081, +3 finalize-abort;
+  manifest specs already counted) · HARD GATE 193/193 · rollback 14/14 · migration 21/21.
+
+### Codex round 3 (pre-push self-review) → blockers D1/D2 fixed red-first (2026-07-16)
+Re-ran codex again; it found two more rollback-path gaps `set -E` cannot catch. Fixed forward, red-first:
+- **Blocker-D1 (CRITICAL) — `find` scan failures swallowed by process substitution.** Both the overlay
+  copy and the scoped prune consumed `< <(find … -print0)`. Bash does NOT propagate the producer's exit
+  status to the `while`, so an EACCES/I/O failure mid-scan truncates the file list yet leaves the loop
+  exiting 0 → a partial upgrade commits and reports success; the ERR/restore trap never fires. Fix:
+  `_scan_or_die` runs `find … -print0 > "$tmp"` to completion, checks its status, and returns non-zero
+  (→ ERR trap → restore) on failure; both loops now read from the checked temp file. Rollback test
+  Part D: a `find` shim that fails every `-print0` scan → shipped installer aborts non-zero + restores +
+  emits "Could not enumerate framework files" + target byte-identical; control neuters the `# D1-GUARD`
+  `return 1` → find failure swallowed, upgrade wrongly reports "file phase complete", no rollback.
+- **Blocker-D2 (CRITICAL) — silent `set -e` exit on a failed target reset.** restore_snapshot did a bare
+  `rm -rf "$TARGET_DIR"; mkdir -p "$TARGET_DIR"` (trap disarmed, under set -e). If `rm`/`mkdir` fails —
+  possibly after `rm` deleted part of the target — the script exits immediately, skipping the cp AND the
+  recovery pointer, leaving a half-removed target and an orphaned snapshot the operator can't locate.
+  Fix: `if ! rm -rf … || ! mkdir -p …; then fail "Snapshot restore could not reset … preserved at:
+  $SNAPSHOT_DIR — copy it back …"; return 1; fi` (tested like the cp -a check; snapshot NOT deleted).
+  Rollback test Part E: cp-poison triggers restore + an `rm` shim fails `rm -rf <TARGET>` → shipped
+  emits the recovery pointer, the named snapshot dir survives, secret value never leaked; control deletes
+  the recovery line → operator gets no pointer. RED: reverting D1+D2 → 7 shipped/control assertions fail.
+- Gates: typecheck ✓ lint ✓ format:check ✓ · full mosaic vitest 1094 · HARD GATE 193/193 ·
+  rollback 28/28 (was 14, +14 for D1/D2 with controls) · migration 21/21. shellcheck clean on new lines.
+  No --no-verify. Committing FORWARD (no rebase of 34e55d4a/0a5e703a).

packages/mosaic/framework/install.sh

@@ -1,5 +1,10 @@
 #!/usr/bin/env bash
-set -euo pipefail
+# -E (errtrace): the ERR trap must propagate INTO functions and command
+# substitutions. Without it the `trap restore_snapshot ERR` set below is dead
+# code for any failure inside sync_framework_keep() (its whole body runs in a
+# function) — a mid-sync failure would abort with a half-written target and NO
+# rollback (#791 B1). Keep -E first so every later function inherits the trap.
+set -Eeuo pipefail
 
 # ─── Mosaic Framework Installer ──────────────────────────────────────────────
 #
@@ -62,14 +67,45 @@ step() { echo -e "\n${BOLD}$1${RESET}"; }
 SNAPSHOT_DIR=""
 make_snapshot() {
   is_existing_install || return 0
+  # mktemp -d creates the dir 0700 — the snapshot (which mirrors operator config,
+  # possibly including secrets) is never world-readable.
   SNAPSHOT_DIR="$(mktemp -d "${TMPDIR:-/tmp}/mosaic-snapshot-XXXXXX")"
-  cp -a "$TARGET_DIR/." "$SNAPSHOT_DIR/" 2>/dev/null || true
+  # The snapshot MUST be complete: restore rebuilds the target from it, so a
+  # partial capture (unreadable file, disk-full, I/O error) would silently
+  # discard whatever it missed. If cp -a cannot copy the whole tree, abort NOW —
+  # before the restore trap is armed and before anything is mutated. Fail closed
+  # rather than proceed with a snapshot we cannot trust (#791 blocker-2).
+  if ! cp -a "$TARGET_DIR/." "$SNAPSHOT_DIR/"; then
+    fail "Could not capture a complete pre-upgrade snapshot of $TARGET_DIR — aborting before any changes were made (fail-closed)."
+    rm -rf "$SNAPSHOT_DIR"; SNAPSHOT_DIR=""
+    exit 1
+  fi
 }
 restore_snapshot() {
+  # Disarm the trap first: restore runs under `set -e`, and a non-zero step
+  # inside it must not re-enter this handler (errtrace makes ERR fire in
+  # functions now). One restore attempt, then let the script exit non-zero.
+  trap - ERR INT TERM
   [[ -n "$SNAPSHOT_DIR" && -d "$SNAPSHOT_DIR" ]] || return 0
   fail "Install interrupted/failed — restoring previous state from snapshot"
-  rm -rf "$TARGET_DIR"; mkdir -p "$TARGET_DIR"
-  cp -a "$SNAPSHOT_DIR/." "$TARGET_DIR/" 2>/dev/null || true
+  # Reset the target before rebuilding from the snapshot — but CHECK it. Under
+  # `set -e` (trap already disarmed) a bare `rm -rf; mkdir -p` that fails would
+  # exit the whole script immediately, after `rm` may have deleted part of the
+  # target, WITHOUT ever printing the recovery pointer below — the operator would
+  # be left with a half-removed target and no idea the snapshot survives in /tmp.
+  # Test the reset explicitly (like the cp -a below), and on failure keep the
+  # snapshot and tell the operator where it is (#791 blocker-D2).
+  if ! rm -rf "$TARGET_DIR" || ! mkdir -p "$TARGET_DIR"; then
+    fail "Snapshot restore could not reset $TARGET_DIR. Your previous configuration is preserved at: $SNAPSHOT_DIR — copy it back into $TARGET_DIR manually."
+    return 1
+  fi
+  # Surface an incomplete restore instead of swallowing it: the snapshot is the
+  # last good copy, so if cp cannot fully rebuild the target we must NOT delete
+  # the snapshot — point the operator at it for manual recovery (#791 blocker-2).
+  if ! cp -a "$SNAPSHOT_DIR/." "$TARGET_DIR/"; then
+    fail "Snapshot restore did not complete cleanly. Your previous configuration is preserved at: $SNAPSHOT_DIR — copy it back into $TARGET_DIR manually."
+    return 1
+  fi
 }
 cleanup_snapshot() { [[ -n "$SNAPSHOT_DIR" && -d "$SNAPSHOT_DIR" ]] && rm -rf "$SNAPSHOT_DIR"; SNAPSHOT_DIR=""; }
 
@@ -174,7 +210,9 @@ sync_framework() {
   if [[ "$INSTALL_MODE" == "keep" ]]; then
     # The `mosaic update` path. Manifest-driven, never-deleting-outside-framework:
     # operator config is structurally protected (#791). No rsync --delete here.
-    manifest_load
+    # The manifest is already loaded+validated in main() BEFORE the snapshot/trap
+    # (a fail-closed manifest must abort without ever restoring over operator
+    # files — see the pre-flight in main, #791 blocker-1).
     sync_framework_keep
     return
   fi
@@ -184,15 +222,36 @@ sync_framework() {
   sync_framework_overwrite
 }
 
+# Enumerate a NUL-delimited file list via `find` into the temp file $1, failing
+# CLOSED if find errors. We capture to a checked file instead of consuming
+# `< <(find …)` directly because a process substitution discards the producer's
+# exit status: an EACCES/I/O failure partway through a scan would truncate the
+# list yet leave the reading `while` loop exiting 0, so a partial upgrade would
+# commit and report success and the ERR/restore trap would never fire. Running
+# find to completion first, then checking its status, turns that silent
+# truncation into a fail-closed abort that the restore trap can act on (#791
+# blocker-D1). $1 after the shift is the scan root — named in the error.
+_scan_or_die() {
+  local out="$1"; shift
+  if ! find "$@" -print0 > "$out"; then
+    fail "Could not enumerate framework files under '$1' — aborting before committing an incomplete sync (fail-closed)."
+    return 1  # D1-GUARD
+  fi
+}
+
 # Keep-mode sync: create/refresh framework-owned files and prune only retired
 # framework files inside shipped framework subtrees. Operator-owned and unknown
 # paths (fail-safe default) are never written and never deleted — the #791 HARD
 # GATE. Single code path (no rsync) so it is byte-for-byte parity-testable.
 sync_framework_keep() {
-  local src="$SOURCE_DIR" dst="$TARGET_DIR" abs rel root
+  local src="$SOURCE_DIR" dst="$TARGET_DIR" abs rel root list
 
   # 1) Overlay copy — every framework-owned source file, refreshed only when its
   #    bytes changed (no mtime churn on unchanged files, never on operator files).
+  #    The source scan is captured fail-closed (#791 blocker-D1): a find failure
+  #    aborts the sync (→ ERR trap → restore) rather than silently truncating it.
+  list="$(mktemp)"
+  _scan_or_die "$list" "$src" -type f || { rm -f "$list"; return 1; }
   while IFS= read -r -d '' abs; do
     rel="${abs#"$src"/}"
     case "$rel" in
@@ -202,24 +261,34 @@ sync_framework_keep() {
     if [[ -f "$dst/$rel" ]] && cmp -s "$abs" "$dst/$rel"; then continue; fi
     [[ "$rel" == */* ]] && mkdir -p "$dst/${rel%/*}"
     cp "$abs" "$dst/$rel"
-  done < <(find "$src" -type f -print0)
+  done < "$list"
+  rm -f "$list"
 
   # 2) Scoped prune — within each shipped framework subtree root, remove
   #    framework-owned target files the current source no longer ships. Operator
   #    carve-outs (e.g. tools/_lib/credentials.json) resolve to operator and are
   #    skipped; unknown paths resolve to operator too — both are unreachable here.
+  #    Each subtree scan is captured fail-closed for the same reason as the copy.
   while IFS= read -r root; do
     [[ -n "$root" && -d "$dst/$root" ]] || continue
+    list="$(mktemp)"
+    _scan_or_die "$list" "$dst/$root" -type f || { rm -f "$list"; return 1; }
     while IFS= read -r -d '' abs; do
       rel="${abs#"$dst"/}"
       case "$rel" in *.pre-constitution.bak) continue ;; esac
       [[ -f "$src/$rel" ]] && continue                          # still shipped
       manifest_is_framework "$rel" || continue
       rm -f "$abs"
-    done < <(find "$dst/$root" -type f -print0)
+    done < "$list"
+    rm -f "$list"
     # Drop framework dirs left empty by the prune (never touches a dir that still
-    # holds an operator file — those are never emptied).
-    find "$dst/$root" -type d -empty -delete 2>/dev/null || true
+    # holds an operator file — those are never emptied). A genuine find failure
+    # (unreadable dir) is surfaced as a warning rather than silently swallowed;
+    # the "directory not empty" races we tolerate are ignored via -delete's own
+    # rc, not by hiding stderr — so a real error is still visible to the operator.
+    if ! find "$dst/$root" -type d -empty -delete 2>/dev/null; then
+      warn "prune: could not fully sweep empty framework dirs under $root (left as-is)"
+    fi
   done < <(manifest_subtree_roots)
 }
 
@@ -307,9 +376,23 @@ else
   ok "Install mode: overwrite"
 fi
 
+# Pre-flight (keep mode): load + validate the framework manifest BEFORE taking a
+# snapshot or arming the restore trap. A fail-closed manifest (missing / empty /
+# malformed) must abort here WITHOUT deleting or restoring over operator files —
+# the snapshot/restore path exists only for a genuine mid-sync mutation failure,
+# not for a validation failure that has touched nothing yet (#791 blocker-1).
+if [[ "$INSTALL_MODE" == "keep" ]]; then
+  manifest_load
+fi
+
 # Snapshot before any destructive file operation; restore on interrupt/failure.
+# The trap MUST exit after restoring: a bash INT/TERM handler that merely returns
+# does NOT terminate the script — execution would resume past the interrupt,
+# clear the snapshot, and report success, leaving a partial post-interrupt update
+# (#791 blocker-A). `restore_snapshot; exit 1` guarantees a non-zero exit for
+# both the errtrace (ERR) and signal (INT/TERM) paths.
 make_snapshot
-trap 'restore_snapshot' ERR INT TERM
+trap 'restore_snapshot; exit 1' ERR INT TERM
 
 sync_framework
 

packages/mosaic/framework/tools/_lib/manifest.sh

@@ -110,6 +110,11 @@ _manifest_compile() {
   local g
   for g in "${MANIFEST_FRAMEWORK[@]:-}"; do [[ -n "$g" ]] && _manifest_compile_one "$g" F; done
   for g in "${MANIFEST_OPERATOR[@]:-}"; do [[ -n "$g" ]] && _manifest_compile_one "$g" O; done
+  # Explicit success: an empty operator array makes the final `[[ -n "" ]] && …`
+  # short-circuit to rc 1, which would otherwise become this function's (and
+  # manifest_load's) return code — a spurious failure (#791 B2). Never rely on
+  # the last loop's exit status here.
+  return 0
 }
 
 # Load + compile the manifest. Rejects a malformed file the same way
@@ -117,6 +122,13 @@ _manifest_compile() {
 manifest_load() {
   local file="${1:-}"
   [[ -n "$file" ]] || file="$(_manifest_default_root)/framework-manifest.txt"
+  # Fail CLOSED on a missing/unreadable manifest. Without this, `done < "$file"`
+  # aborts on a raw redirection error with no explanation; downstream that reads
+  # as "no framework paths" and an upgrade could no-op silently (#791 B2/B3).
+  if [[ ! -r "$file" ]]; then
+    echo "manifest: cannot read manifest file: $file — refusing to sync (fail-closed)." >&2
+    return 1
+  fi
   MANIFEST_FRAMEWORK=()
   MANIFEST_OPERATOR=()
   local section="" line
@@ -139,7 +151,30 @@ manifest_load() {
       MANIFEST_OPERATOR+=("$line")
     fi
   done < "$file"
+  # An empty or comment-only manifest defines NO framework-owned paths. Treating
+  # that as valid would make every path resolve operator and an upgrade prune
+  # nothing / write nothing — a silent no-op indistinguishable from success.
+  # Fail loud instead, mirroring parseManifest()'s throw in manifest.ts (#791 B2).
+  if [[ ${#MANIFEST_FRAMEWORK[@]} -eq 0 ]]; then
+    echo "manifest: no [framework] entries in $file — refusing to sync (empty or malformed manifest)." >&2
+    return 1
+  fi
+  # An entry like `/` or `./` normalizes to nothing and compiles to a glob that
+  # matches no path — so a manifest whose only [framework] entries are degenerate
+  # passes the count guard above but leaves the framework matcher empty: every
+  # path resolves operator, the exact silent no-op we fail closed against. Require
+  # at least one entry with a real (non-slash, non-dot) character. Mirrors
+  # parseManifest()'s `isUsableFrameworkGlob` `/[^/.]/` test in manifest.ts (#791 blocker-B).
+  local _g _usable=0
+  for _g in "${MANIFEST_FRAMEWORK[@]:-}"; do
+    if [[ "$(_manifest_norm "$_g")" =~ [^/.] ]]; then _usable=1; break; fi
+  done
+  if [[ "$_usable" -eq 0 ]]; then
+    echo "manifest: no usable [framework] entries in $file (every entry is empty or a bare dot segment) — refusing to sync (malformed manifest)." >&2
+    return 1
+  fi
   _manifest_compile
+  return 0
 }
 
 # Fork-free: does $1 (a mosaic-home-relative path) match an operator glob?
@@ -196,7 +231,10 @@ manifest_subtree_roots() {
 # CLI dispatch — only when executed directly, never when sourced.
 if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
   set -o pipefail
-  manifest_load "${MANIFEST_FILE:-}"
+  # Propagate a fail-closed manifest_load (missing/empty/malformed) as a non-zero
+  # exit instead of continuing to resolve against empty compiled arrays — that is
+  # what lets the parity test assert bash and TS reject the same bad inputs (#791 B2).
+  manifest_load "${MANIFEST_FILE:-}" || exit 1
   cmd="${1:-}"
   case "$cmd" in
     resolve) manifest_resolve "${2:?path required}" ;;

packages/mosaic/framework/tools/quality/scripts/test-upgrade-manifest-guard.sh

@@ -9,8 +9,16 @@
 # must still update, and a retired framework file inside a shipped subtree must
 # still be pruned. No operator secret value may appear in installer output.
 #
-# Runs the whole matrix twice: once with rsync available, once forcing the
-# cp-based fallback (both destructive paths in install.sh must obey the manifest).
+# Keep mode is a SINGLE code path (sync_framework_keep, a manifest-driven cp
+# overlay + scoped prune — no rsync). The matrix still runs twice, once with
+# rsync on PATH and once with it hidden, to prove the keep path is genuinely
+# rsync-independent: it must obey the manifest identically whether or not rsync
+# happens to be installed (rsync --delete is only ever used by overwrite mode,
+# which has no operator state to protect).
+#
+# It also runs a fail-closed matrix (#791 B2/B3): an empty, operator-only,
+# malformed, or missing manifest must ABORT the upgrade loudly and leave every
+# operator path untouched — never silently no-op to "complete".
 #
 # Usage:  bash test-upgrade-manifest-guard.sh
 set -uo pipefail
@@ -131,6 +139,59 @@ run_matrix() {
   rm -rf "$H" "$E" "$OUT"
 }
 
+# Fail-closed matrix (#791 B2/B3 + blocker-1): run install.sh from a COPY of the
+# framework so the shipped manifest can be corrupted. Every corruption must abort
+# the upgrade non-zero with a manifest error, leaving all operator sentinels
+# byte-identical AND on the SAME inode. The inode check is the load-bearing part:
+# manifest validation is hoisted BEFORE make_snapshot/the restore trap, so a bad
+# manifest must abort without ever snapshotting, deleting, and restoring the
+# target. Were validation still armed under the ERR trap, restore_snapshot would
+# rm -rf + rebuild the target — same bytes but a NEW inode (broken hard links,
+# changed ctime), which a content-only hash would miss (#791 blocker-1).
+run_failclosed() {
+  local label="$1" mutate="$2"
+  local SRC H E OUT rc rel before_hash after_hash before_ino after_ino key
+  SRC=$(mktemp -d); H=$(mktemp -d); E=$(mktemp -d); OUT=$(mktemp)
+  cp -a "$FW/." "$SRC/"
+  case "$mutate" in
+    empty)         : > "$SRC/framework-manifest.txt" ;;
+    operator-only) printf '[operator]\nSOUL.md\n*.local.md\n' > "$SRC/framework-manifest.txt" ;;
+    malformed)     printf 'stray.md\n[framework]\nguides/**\n' > "$SRC/framework-manifest.txt" ;;
+    degenerate)    printf '[framework]\n/\n./\n[operator]\nSOUL.md\n' > "$SRC/framework-manifest.txt" ;;
+    missing)       rm -f "$SRC/framework-manifest.txt" ;;
+  esac
+
+  seed_home "$H"
+  for rel in "${OPERATOR_SENTINELS[@]}"; do
+    key=$(echo "$rel" | tr / _)
+    sha256sum "$H/$rel" | awk '{print $1}' > "$E/$key.hash"
+    stat -c '%i' "$H/$rel" > "$E/$key.ino"
+  done
+
+  MOSAIC_HOME="$H" MOSAIC_INSTALL_MODE=keep MOSAIC_SYNC_ONLY=1 bash "$SRC/install.sh" >"$OUT" 2>&1
+  rc=$?
+
+  chk "[fail-closed:$label] upgrade aborts non-zero" "[ '$rc' -ne 0 ]"
+  chk "[fail-closed:$label] refuses loudly with a manifest error" \
+    "grep -qi 'manifest' '$OUT'"
+  for rel in "${OPERATOR_SENTINELS[@]}"; do
+    key=$(echo "$rel" | tr / _)
+    before_hash=$(cat "$E/$key.hash")
+    after_hash=$(sha256sum "$H/$rel" 2>/dev/null | awk '{print $1}')
+    chk "[fail-closed:$label] operator sentinel untouched: $rel" \
+      "[ -n '$after_hash' ] && [ '$before_hash' = '$after_hash' ]"
+    before_ino=$(cat "$E/$key.ino")
+    after_ino=$(stat -c '%i' "$H/$rel" 2>/dev/null)
+    chk "[fail-closed:$label] operator sentinel not deleted/recreated (inode stable): $rel" \
+      "[ -n '$after_ino' ] && [ '$before_ino' = '$after_ino' ]"
+  done
+  chk "[fail-closed:$label] operator secret value absent from output" \
+    "! grep -q '$SECRET' '$OUT'"
+
+  chmod -R u+w "$SRC" "$H" 2>/dev/null || true
+  rm -rf "$SRC" "$H" "$E" "$OUT"
+}
+
 echo "#791 upgrade manifest guard (HARD GATE):"
 
 # 1) rsync path (if available on this host).
@@ -140,15 +201,24 @@ else
   echo "  · rsync not installed — skipping rsync-path matrix"
 fi
 
-# 2) cp fallback path — hide rsync behind a scratch PATH so install.sh takes the
-#    find/rm+cp branch. Provide the coreutils the fallback needs.
+# 2) rsync-absent path — hide rsync behind a scratch PATH. Keep mode never calls
+#    rsync, so this must resolve identically to run (1); it proves the keep path
+#    does not silently depend on rsync being installed. (Provide the coreutils the
+#    installer needs on the stripped PATH.)
 FBIN=$(mktemp -d)
 for t in bash cp find mktemp rm mkdir chmod cmp sed grep cat dirname basename stat sha256sum awk tr; do
   p=$(command -v "$t" 2>/dev/null) && ln -s "$p" "$FBIN/$t"
 done
-run_matrix "cp-fallback" env "PATH=$FBIN"
+run_matrix "rsync-absent" env "PATH=$FBIN"
 rm -rf "$FBIN"
 
+# 3) fail-closed matrix (#791 B2/B3) — corrupt the shipped manifest four ways.
+run_failclosed "empty-manifest"       empty
+run_failclosed "operator-only"        operator-only
+run_failclosed "malformed-manifest"   malformed
+run_failclosed "degenerate-framework" degenerate
+run_failclosed "missing-manifest"     missing
+
 echo
 echo "RESULT: $pass passed, $fail failed"
 [ "$fail" -eq 0 ]

packages/mosaic/framework/tools/quality/scripts/test-upgrade-rollback.sh

@@ -0,0 +1,319 @@
+#!/usr/bin/env bash
+# test-upgrade-rollback.sh — the #791 B1 regression gate.
+#
+# A keep-mode upgrade takes a pre-update snapshot and installs an ERR/INT/TERM
+# trap that restores it if the sync aborts midway (install.sh: make_snapshot +
+# `trap restore_snapshot`). That trap is only reached if `set -E` (errtrace) is
+# active — otherwise a failure INSIDE sync_framework_keep() (which runs entirely
+# in a function) never fires the trap, and the upgrade aborts leaving a
+# half-written target with NO rollback. This test proves:
+#
+#   Part A (the gate):   the shipped installer rolls back a mid-sync failure —
+#                        the restore message fires, the corrupted file is put
+#                        back, AND the whole target is byte-identical to its
+#                        pre-upgrade state.
+#   Part B (the control): the SAME installer with `-E` stripped does NOT roll back
+#                        (dead trap) — the mid-sync corruption survives, proving
+#                        errtrace is load-bearing. If anyone removes `set -E`,
+#                        Part A goes red.
+#
+# The mid-sync failure is injected with a PATH-shadowing `cp` shim rather than
+# file permissions. The earlier 0400/EACCES approach was NOT portable: Woodpecker
+# runs steps as root (node:24-alpine has no USER directive), and root overwrites a
+# 0400 file, so the failure never fired and this gate silently passed (#791
+# blocker-3). The shim fails deterministically for one framework-owned
+# destination regardless of uid, and — like a real interrupted cp (disk-full
+# mid-write) — leaves a partially-written target behind, so rollback has real
+# damage to undo and the control has real damage to expose.
+#
+# Usage:  bash test-upgrade-rollback.sh
+set -uo pipefail
+
+FW="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"   # packages/mosaic/framework
+INSTALL="$FW/install.sh"
+ORIG_PATH="$PATH"
+
+# The `-E`-stripped control installer must live INSIDE $FW: install.sh derives
+# SOURCE_DIR from its own path and `source`s $SOURCE_DIR/tools/_lib/manifest.sh,
+# so a copy anywhere else aborts at the source line before ever reaching the sync
+# loop — which would make the control a false negative. A root dotfile is
+# operator-owned (unknown→operator), so the sync loop skips it. Clean up on exit.
+STRIPPED="$FW/.install-rollback-control.tmp.sh"
+NOEXIT="$FW/.install-noexit-control.tmp.sh"
+D1CTRL="$FW/.install-d1guard-control.tmp.sh"
+D2CTRL="$FW/.install-d2guard-control.tmp.sh"
+rm -f "$STRIPPED" "$NOEXIT" "$D1CTRL" "$D2CTRL"
+trap 'rm -f "$STRIPPED" "$NOEXIT" "$D1CTRL" "$D2CTRL"' EXIT
+
+pass=0; fail=0
+chk() { if eval "$2"; then echo "  ✓ $1"; pass=$((pass + 1)); else echo "  ✗ $1"; fail=$((fail + 1)); fi; }
+
+SECRET='SUPER-SECRET-TOKEN-do-not-log-b1'
+# A framework-owned file the shim fails the copy of. The seeded target holds GOOD
+# bytes; source ships different bytes, so sync_framework_keep() attempts the copy
+# and the shim intercepts it. Root-level framework files sort before guides/, so
+# several framework files are already refreshed when the copy reaches this one.
+POISON_REL='guides/E2E-DELIVERY.md'
+GOOD='GOOD-REFERENCE-CONTENT-pre-upgrade-b1'
+GARBAGE='PARTIAL-WRITE-GARBAGE-mid-sync-b1'
+
+# A `cp` shim: for the poisoned destination, simulate an interrupted copy — write
+# partial garbage to the target, then fail — otherwise delegate to the real cp
+# (resolved via the ORIGINAL PATH so make_snapshot/restore still work).
+make_cp_shim() {
+  local dir="$1"
+  cat > "$dir/cp" <<SHIM
+#!/usr/bin/env bash
+dest="\${@: -1}"
+case "\$dest" in
+  */$POISON_REL)
+    printf '%s' '$GARBAGE' > "\$dest" 2>/dev/null || true
+    exit 1 ;;
+esac
+exec env PATH="$ORIG_PATH" cp "\$@"
+SHIM
+  chmod +x "$dir/cp"
+}
+
+# A `find` shim that fails every enumeration scan (`-print0`) as if it hit an
+# EACCES/I/O error partway — it emits the real (here: complete) list first, then
+# exits non-zero, exactly the class of failure a `< <(find …)` process
+# substitution silently swallows. All non-`-print0` finds (e.g. the -delete
+# sweep) delegate to the real find on the original PATH. Used to prove #791
+# blocker-D1: the shipped installer must honor find's exit status and roll back.
+make_find_fail_shim() {
+  local dir="$1"
+  cat > "$dir/find" <<SHIM
+#!/usr/bin/env bash
+for a in "\$@"; do
+  if [ "\$a" = "-print0" ]; then
+    env PATH="$ORIG_PATH" find "\$@"   # emit the real list…
+    exit 1                              # …then fail as if the scan hit EACCES
+  fi
+done
+exec env PATH="$ORIG_PATH" find "\$@"
+SHIM
+  chmod +x "$dir/find"
+}
+
+# An `rm` shim that fails ONLY `rm -rf <FAIL_RM_TARGET>` (the restore's target
+# reset) and delegates every other rm to the real one. Used to prove #791
+# blocker-D2: when the target reset inside restore_snapshot fails, the installer
+# must emit the manual-recovery pointer (snapshot path) instead of exiting
+# silently under `set -e`. FAIL_RM_TARGET is exported into the installer env.
+make_rm_fail_shim() {
+  local dir="$1"
+  cat > "$dir/rm" <<'SHIM'
+#!/usr/bin/env bash
+last="${@: -1}"
+if [ -n "${FAIL_RM_TARGET:-}" ] && [ "$last" = "$FAIL_RM_TARGET" ]; then
+  exit 1
+fi
+exec env PATH="$ORIG_PATH_FOR_RM" rm "$@"
+SHIM
+  chmod +x "$dir/rm"
+}
+
+seed_home() {
+  local H="$1"
+  mkdir -p "$H/agents" "$H/tools/_lib" "$H/memory" "$H/guides"
+  printf '# persona\n' > "$H/SOUL.md"          # recognized install → keep mode + snapshot
+  printf 'MODEL=opus\n' > "$H/agents/coder0.conf"
+  printf '# operator memory\n' > "$H/memory/note.md"
+  printf 'TOKEN=%s\n' "$SECRET" > "$H/tools/_lib/credentials.json"
+  echo 3 > "$H/.framework-version"
+  # Good pre-upgrade bytes; source ships different bytes, so cp is attempted.
+  printf '%s' "$GOOD" > "$H/$POISON_REL"
+}
+
+# Run one keep-mode upgrade against $1=installer, seeding a fresh home and a
+# byte-for-byte reference of the pre-upgrade state, with the cp shim first on
+# PATH. Echoes: "<exit>\t<out>\t<ref>\t<home>".
+run_upgrade() {
+  local installer="$1" shim_maker="${2:-make_cp_shim}" H REF OUT SHIM rc
+  H=$(mktemp -d); REF=$(mktemp -d); OUT=$(mktemp); SHIM=$(mktemp -d)
+  seed_home "$H"
+  env PATH="$ORIG_PATH" cp -a "$H/." "$REF/"     # pre-upgrade reference (real cp)
+  "$shim_maker" "$SHIM"
+  set +e
+  PATH="$SHIM:$ORIG_PATH" \
+    MOSAIC_HOME="$H" MOSAIC_INSTALL_MODE=keep MOSAIC_SYNC_ONLY=1 bash "$installer" >"$OUT" 2>&1
+  rc=$?
+  set -e 2>/dev/null || true
+  rm -rf "$SHIM"
+  printf '%s\t%s\t%s\t%s\n' "$rc" "$OUT" "$REF" "$H"
+}
+
+echo "#791 upgrade rollback (B1 regression gate):"
+
+# ── Part A: the shipped installer must roll back a mid-sync failure ───────────
+IFS=$'\t' read -r rcA OUTA REFA HA < <(run_upgrade "$INSTALL")
+
+chk "[shipped] upgrade aborts non-zero on the injected mid-sync failure" \
+  "[ '$rcA' -ne 0 ]"
+chk "[shipped] restore_snapshot fires (rollback message present)" \
+  "grep -q 'restoring previous state from snapshot' '$OUTA'"
+chk "[shipped] the corrupted file is restored to its pre-upgrade bytes" \
+  "[ \"\$(cat '$HA/$POISON_REL')\" = '$GOOD' ]"
+chk "[shipped] target rolled back byte-identical to pre-upgrade state" \
+  "diff -r '$REFA' '$HA' >/dev/null 2>&1"
+chk "[shipped] operator secret value absent from installer output" \
+  "! grep -q '$SECRET' '$OUTA'"
+
+# ── Part B: control — strip `-E`, the trap is dead, no rollback happens ───────
+# Proves errtrace is what makes the trap reachable. If `set -E` is ever removed
+# from install.sh, Part A's rollback assertions fail exactly like this control.
+sed 's/^set -Eeuo pipefail/set -euo pipefail/' "$INSTALL" > "$STRIPPED"
+chk "[control] the -E strip actually changed the installer" \
+  "! cmp -s '$INSTALL' '$STRIPPED'"
+
+IFS=$'\t' read -r rcB OUTB REFB HB < <(run_upgrade "$STRIPPED")
+chk "[control] without -E the upgrade still aborts non-zero" \
+  "[ '$rcB' -ne 0 ]"
+# The load-bearing, deterministic proof of B1: without errtrace the ERR trap
+# never fires for a failure inside sync_framework_keep(), so no rollback runs.
+chk "[control] without -E the rollback message does NOT fire (dead trap)" \
+  "! grep -q 'restoring previous state from snapshot' '$OUTB'"
+chk "[control] without -E the mid-sync corruption survives (no rollback)" \
+  "[ \"\$(cat '$HB/$POISON_REL')\" = '$GARBAGE' ]"
+
+# ── Part C: an INT/TERM interrupt must terminate, not resume (blocker-A) ──────
+# A bash signal trap that merely returns lets the script continue past the
+# interrupt — restoring the snapshot, then resuming the sync and reporting
+# success. We inject a SIGTERM mid-sync with a cp that SUCCEEDS (so set -e never
+# fires and ONLY the signal path governs), and assert the shipped installer
+# restores AND exits without reporting success. The control strips `exit 1` from
+# the trap and shows the buggy resume-to-success.
+make_term_shim() {
+  local dir="$1"
+  cat > "$dir/cp" <<SHIM
+#!/usr/bin/env bash
+dest="\${@: -1}"
+case "\$dest" in
+  */$POISON_REL)
+    kill -TERM "\$PPID" 2>/dev/null   # signal install.sh; the copy still succeeds
+    exec env PATH="$ORIG_PATH" cp "\$@" ;;
+esac
+exec env PATH="$ORIG_PATH" cp "\$@"
+SHIM
+  chmod +x "$dir/cp"
+}
+
+# Run one keep-mode upgrade with the SIGTERM shim. Echoes "<exit>\t<out>\t<home>".
+run_signal_upgrade() {
+  local installer="$1" H OUT SHIM rc
+  H=$(mktemp -d); OUT=$(mktemp); SHIM=$(mktemp -d)
+  seed_home "$H"
+  make_term_shim "$SHIM"
+  set +e
+  PATH="$SHIM:$ORIG_PATH" \
+    MOSAIC_HOME="$H" MOSAIC_INSTALL_MODE=keep MOSAIC_SYNC_ONLY=1 bash "$installer" >"$OUT" 2>&1
+  rc=$?
+  set -e 2>/dev/null || true
+  rm -rf "$SHIM"
+  printf '%s\t%s\t%s\n' "$rc" "$OUT" "$H"
+}
+
+IFS=$'\t' read -r rcC OUTC HC < <(run_signal_upgrade "$INSTALL")
+chk "[signal] SIGTERM mid-sync aborts non-zero (trap exits, does not resume)" \
+  "[ '$rcC' -ne 0 ]"
+chk "[signal] restore_snapshot fires on the interrupt" \
+  "grep -q 'restoring previous state from snapshot' '$OUTC'"
+chk "[signal] does NOT resume to report sync success after the interrupt" \
+  "! grep -q 'file phase complete' '$OUTC'"
+
+# Control: strip `exit 1` from the signal trap → the handler returns, the script
+# resumes past the interrupt and wrongly reports success. In $FW so SOURCE_DIR resolves.
+sed "s/trap 'restore_snapshot; exit 1' ERR INT TERM/trap 'restore_snapshot' ERR INT TERM/" \
+  "$INSTALL" > "$NOEXIT"
+chk "[control] the exit-strip actually changed the installer" \
+  "! cmp -s '$INSTALL' '$NOEXIT'"
+IFS=$'\t' read -r _rcD OUTD HD < <(run_signal_upgrade "$NOEXIT")
+chk "[control] without 'exit 1' the trap resumes and reports sync success (the bug)" \
+  "grep -q 'file phase complete' '$OUTD'"
+
+# ── Part D: a failed source/prune `find` scan must abort + roll back (D1) ─────
+# A `< <(find …)` process substitution discards find's exit status, so an
+# EACCES/I/O failure mid-scan would truncate the file list yet leave the reading
+# loop exiting 0 — a partial upgrade committed and reported as success, with the
+# ERR/restore trap never firing. The shipped installer captures the scan into a
+# checked temp file (_scan_or_die) and aborts on failure. We inject a `find` that
+# fails every `-print0` scan and assert the shipped installer rolls back.
+IFS=$'\t' read -r rcE OUTE REFE HE < <(run_upgrade "$INSTALL" make_find_fail_shim)
+chk "[find-fail] a failing framework scan aborts the upgrade non-zero" \
+  "[ '$rcE' -ne 0 ]"
+chk "[find-fail] restore_snapshot fires on the aborted scan" \
+  "grep -q 'restoring previous state from snapshot' '$OUTE'"
+chk "[find-fail] the abort is a fail-closed enumeration error (not a silent truncation)" \
+  "grep -q 'Could not enumerate framework files' '$OUTE'"
+chk "[find-fail] target rolled back byte-identical to pre-upgrade state" \
+  "diff -r '$REFE' '$HE' >/dev/null 2>&1"
+
+# Control: neuter the D1 guard (turn its `return 1` into a no-op) so a find
+# failure is swallowed exactly as `< <(find …)` would — the scan appears to
+# succeed and the upgrade reports completion with NO rollback.
+sed 's/return 1  # D1-GUARD/: # D1-GUARD-DISABLED/' "$INSTALL" > "$D1CTRL"
+chk "[control] the D1-guard strip actually changed the installer" \
+  "! cmp -s '$INSTALL' '$D1CTRL'"
+IFS=$'\t' read -r _rcF OUTF REFF HF < <(run_upgrade "$D1CTRL" make_find_fail_shim)
+chk "[control] with the D1 guard disabled the find failure is swallowed (no rollback)" \
+  "! grep -q 'restoring previous state from snapshot' '$OUTF'"
+chk "[control] with the D1 guard disabled the upgrade wrongly reports success" \
+  "grep -q 'file phase complete' '$OUTF'"
+
+# ── Part E: a failed target reset inside restore must not exit silently (D2) ──
+# restore_snapshot resets the target (`rm -rf; mkdir -p`) before rebuilding from
+# the snapshot. Under `set -e` (trap disarmed) a bare reset that fails would exit
+# the whole script immediately — after `rm` may have deleted part of the target —
+# WITHOUT printing where the snapshot lives. We trigger a rollback (cp poison) AND
+# fail the target reset (rm shim), then assert the shipped installer emits the
+# manual-recovery pointer and preserves the snapshot.
+run_rmfail_upgrade() {
+  local installer="$1" H OUT SHIM rc
+  H=$(mktemp -d); OUT=$(mktemp); SHIM=$(mktemp -d)
+  seed_home "$H"
+  make_cp_shim "$SHIM"        # poison cp → triggers the abort + restore
+  make_rm_fail_shim "$SHIM"   # rm -rf <H> fails → exercises the D2 reset guard
+  set +e
+  PATH="$SHIM:$ORIG_PATH" ORIG_PATH_FOR_RM="$ORIG_PATH" FAIL_RM_TARGET="$H" \
+    MOSAIC_HOME="$H" MOSAIC_INSTALL_MODE=keep MOSAIC_SYNC_ONLY=1 bash "$installer" >"$OUT" 2>&1
+  rc=$?
+  set -e 2>/dev/null || true
+  rm -rf "$SHIM"
+  printf '%s\t%s\t%s\n' "$rc" "$OUT" "$H"
+}
+
+IFS=$'\t' read -r rcG OUTG HG < <(run_rmfail_upgrade "$INSTALL")
+chk "[reset-fail] a failed target reset still aborts non-zero" \
+  "[ '$rcG' -ne 0 ]"
+chk "[reset-fail] the manual-recovery pointer is emitted (not a silent set -e exit)" \
+  "grep -q 'Snapshot restore could not reset' '$OUTG'"
+chk "[reset-fail] the recovery message points at a preserved snapshot dir" \
+  "grep -q 'preserved at: .*mosaic-snapshot' '$OUTG'"
+SNAP_E="$(grep -o '/[^ ]*mosaic-snapshot[^ ]*' "$OUTG" | head -1)"
+chk "[reset-fail] the named snapshot directory actually survives for recovery" \
+  "[ -n '$SNAP_E' ] && [ -d '$SNAP_E' ]"
+chk "[reset-fail] operator secret value never appears in installer output" \
+  "! grep -q '$SECRET' '$OUTG'"
+
+# Control: delete the D2 recovery line so a failed reset returns non-zero with NO
+# operator pointer — the observable defect (half-reset target, snapshot orphaned
+# in /tmp with no path told to the operator). Proves the message is load-bearing.
+sed '/Snapshot restore could not reset/d' "$INSTALL" > "$D2CTRL"
+chk "[control] the D2-recovery strip actually changed the installer" \
+  "! cmp -s '$INSTALL' '$D2CTRL'"
+IFS=$'\t' read -r _rcH OUTH HH < <(run_rmfail_upgrade "$D2CTRL")
+chk "[control] without the D2 recovery line the operator gets no snapshot pointer" \
+  "! grep -q 'Snapshot restore could not reset' '$OUTH'"
+[ -n "${SNAP_E:-}" ] && rm -rf "$SNAP_E"
+# Reap any snapshot the reset-fail runs left in /tmp (reset failed → never cleaned).
+grep -o '/[^ ]*mosaic-snapshot[^ ]*' "$OUTH" 2>/dev/null | head -1 | while read -r s; do rm -rf "$s"; done
+
+# Cleanup ($STRIPPED / $NOEXIT / $D1CTRL / $D2CTRL are also removed by the EXIT trap).
+for d in "$HA" "$REFA" "$HB" "$REFB" "$HC" "$HD" "$HE" "$REFE" "$HF" "$REFF" "$HG" "$HH"; do rm -rf "$d"; done
+rm -f "$OUTA" "$OUTB" "$OUTC" "$OUTD" "$OUTE" "$OUTF" "$OUTG" "$OUTH" \
+  "$STRIPPED" "$NOEXIT" "$D1CTRL" "$D2CTRL"
+
+echo
+echo "RESULT: $pass passed, $fail failed"
+[ "$fail" -eq 0 ]

packages/mosaic/src/framework/manifest-parity.spec.ts

@@ -1,6 +1,6 @@
 import { afterAll, describe, it, expect } from 'vitest';
-import { execFileSync } from 'node:child_process';
-import { existsSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs';
+import { execFileSync, spawnSync } from 'node:child_process';
+import { existsSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { fileURLToPath } from 'node:url';
@@ -55,6 +55,19 @@ function bashSubtreeRoots(): string[] {
     .filter((s) => s.length > 0);
 }
 
+/**
+ * Drive the bash resolver CLI against a manifest file and report how it exited.
+ * A fail-closed manifest must make the CLI exit non-zero with a message on
+ * stderr — never exit 0 having silently resolved everything to operator.
+ */
+function bashCli(manifestFile: string): { status: number; stderr: string } {
+  const res = spawnSync('bash', [MANIFEST_SH, 'resolve', 'CONSTITUTION.md'], {
+    encoding: 'utf-8',
+    env: { ...process.env, MANIFEST_FILE: manifestFile },
+  });
+  return { status: res.status ?? -1, stderr: res.stderr ?? '' };
+}
+
 // Paths spanning every ownership class: framework single-files, framework
 // subtrees, operator declared trees, operator carve-out inside a framework
 // subtree, local overlays, and deliberately UNANTICIPATED paths (fail-safe).
@@ -250,3 +263,81 @@ describe.skipIf(!hasBash)('bash ↔ TS manifest format-edge parity (§6.1, Decis
     ]);
   });
 });
+
+/**
+ * Failure-mode parity (#791 B2/B3). A bad manifest is the dangerous case: if the
+ * two resolvers DISAGREED on rejection — one throwing while the other quietly
+ * resolved everything to operator — an upgrade could fail loud on one code path
+ * and no-op on the other. So for every malformed/empty/missing manifest, BOTH
+ * must reject: TS throws, and the bash CLI exits non-zero with a stderr message.
+ */
+describe.skipIf(!hasBash)('bash ↔ TS manifest failure-mode parity (§6.1, B2/B3)', () => {
+  const tmp = mkdtempSync(join(tmpdir(), 'mf-failmode-'));
+  afterAll(() => rmSync(tmp, { recursive: true, force: true }));
+
+  let seq = 0;
+  function writeFixture(text: string): string {
+    const file = join(tmp, `bad-manifest-${seq++}.txt`);
+    writeFileSync(file, text);
+    return file;
+  }
+
+  // TS throws AND bash CLI exits non-zero with a non-empty stderr — identical rejection.
+  function expectBothReject(label: string, manifestFile: string): void {
+    expect(() => parseManifestFile(manifestFile), `TS accepted ${label}`).toThrow();
+    const cli = bashCli(manifestFile);
+    expect(cli.status, `bash did not exit non-zero for ${label}`).not.toBe(0);
+    expect(cli.stderr.trim().length, `bash was silent for ${label}`).toBeGreaterThan(0);
+  }
+
+  // Read the file for the TS side the same way loadManifest does, so both halves
+  // see identical bytes (loadManifest keys off a directory, not an arbitrary file).
+  function parseManifestFile(file: string): void {
+    parseManifest(readFileSync(file, 'utf-8'));
+  }
+
+  it('both reject a completely empty manifest', () => {
+    expectBothReject('empty', writeFixture(''));
+  });
+
+  it('both reject a comment/blank-only manifest', () => {
+    expectBothReject('comment-only', writeFixture('# header only\n\n   \n'));
+  });
+
+  it('both reject an operator-only manifest (zero framework paths)', () => {
+    expectBothReject('operator-only', writeFixture('[operator]\nSOUL.md\n*.local.md\n'));
+  });
+
+  it('both reject a [framework] section with no entries', () => {
+    expectBothReject('empty-framework-section', writeFixture('[framework]\n[operator]\nSOUL.md\n'));
+  });
+
+  it('both reject a [framework] entry that normalizes to an empty glob (/)', () => {
+    expectBothReject('root-slash-framework', writeFixture('[framework]\n/\n'));
+  });
+
+  it('both reject a [framework] entry that normalizes to nothing (./)', () => {
+    expectBothReject('dot-slash-framework', writeFixture('[framework]\n./\n[operator]\nSOUL.md\n'));
+  });
+
+  it('both reject [framework] entries that are only bare dot segments', () => {
+    expectBothReject('bare-dot-framework', writeFixture('[framework]\n.\n..\n'));
+  });
+
+  it('both reject an entry that appears before any section header', () => {
+    expectBothReject('entry-before-header', writeFixture('stray.md\n[framework]\nguides/**\n'));
+  });
+
+  it('both reject an unknown section header', () => {
+    expectBothReject('unknown-header', writeFixture('[bogus]\nx\n'));
+  });
+
+  it('both reject a missing manifest file (fail-closed, not empty result)', () => {
+    const missing = join(tmp, 'does-not-exist.txt');
+    // TS: loadManifest would throw a read error; here read-then-parse throws on read.
+    expect(() => parseManifestFile(missing)).toThrow();
+    const cli = bashCli(missing);
+    expect(cli.status).not.toBe(0);
+    expect(cli.stderr.trim().length).toBeGreaterThan(0);
+  });
+});

packages/mosaic/src/framework/manifest.spec.ts

@@ -9,6 +9,7 @@ import {
   resolveOwnership,
   frameworkSubtreeRoots,
   planPrune,
+  ManifestError,
   type FrameworkManifest,
 } from './manifest.js';
 
@@ -49,6 +50,69 @@ describe('parseManifest', () => {
   });
 });
 
+// Fail-closed parsing/loading (#791 B2/B3). An empty, comment-only, operator-only,
+// or unreadable manifest must NOT resolve to "framework owns nothing" (which would
+// make an upgrade a silent no-op). Both must throw so finalizeStage surfaces the
+// abort instead of reporting "Installation complete". The bash reader rejects the
+// same inputs — asserted for parity in manifest-parity.spec.ts.
+describe('parseManifest / loadManifest fail closed on empty or unreadable input', () => {
+  it('throws on a completely empty manifest', () => {
+    expect(() => parseManifest('')).toThrow(/no \[framework\] paths/);
+  });
+
+  it('throws on a comment- and blank-only manifest (no entries at all)', () => {
+    expect(() => parseManifest('# just a header comment\n\n   \n')).toThrow(
+      /no \[framework\] paths/,
+    );
+  });
+
+  it('throws when only an [operator] section is present (zero framework paths)', () => {
+    expect(() => parseManifest('[operator]\nSOUL.md\n*.local.md\n')).toThrow(
+      /no \[framework\] paths/,
+    );
+  });
+
+  it('throws on a [framework] header with no entries beneath it', () => {
+    expect(() => parseManifest('[framework]\n\n[operator]\nSOUL.md\n')).toThrow(
+      /no \[framework\] paths/,
+    );
+  });
+
+  // Degenerate framework entries that pass the length check but normalize to a
+  // glob matching nothing — the manifest would silently protect the whole tree
+  // as operator (#791 blocker-B). Both `/` and `./` normalize to '' ; `.`/`..`
+  // are bare-dot segments.
+  it.each([['/'], ['./'], ['.'], ['..'], ['/\n./']])(
+    'throws when the only [framework] entry (%j) normalizes to nothing usable',
+    (entry) => {
+      expect(() => parseManifest(`[framework]\n${entry}\n`)).toThrow(
+        /no usable \[framework\] paths/,
+      );
+    },
+  );
+
+  it('accepts a wildcard-only framework glob (** is usable)', () => {
+    expect(() => parseManifest('[framework]\n**\n')).not.toThrow();
+  });
+
+  it('loadManifest throws a clear fail-closed error when the manifest file is missing', () => {
+    const missingRoot = fileURLToPath(new URL('./__no_such_framework_root__', import.meta.url));
+    expect(() => loadManifest(missingRoot)).toThrow(/Cannot read framework manifest/);
+  });
+
+  // The distinct error type is what lets finalizeStage tell a pre-sync validation
+  // abort (nothing written) from a mid-sync filesystem failure (#791 blocker-C).
+  it('every fail-closed rejection is a ManifestError', () => {
+    expect(() => parseManifest('')).toThrow(ManifestError);
+    expect(() => parseManifest('[operator]\nSOUL.md\n')).toThrow(ManifestError);
+    expect(() => parseManifest('[framework]\n/\n')).toThrow(ManifestError);
+    expect(() => parseManifest('[bogus]\nx\n')).toThrow(ManifestError);
+    expect(() => parseManifest('stray.md\n[framework]\n')).toThrow(ManifestError);
+    const missingRoot = fileURLToPath(new URL('./__no_such_framework_root__', import.meta.url));
+    expect(() => loadManifest(missingRoot)).toThrow(ManifestError);
+  });
+});
+
 describe('matchGlob', () => {
   it('matches an exact file', () => {
     expect(matchGlob('CONSTITUTION.md', 'CONSTITUTION.md')).toBe(true);

packages/mosaic/src/framework/manifest.ts

@@ -15,6 +15,19 @@ import { readFileSync } from 'node:fs';
 
 export type Ownership = 'framework' | 'operator';
 
+/**
+ * Thrown when the manifest is missing, empty, or malformed. A distinct type lets
+ * callers (e.g. finalizeStage) tell a pre-sync validation abort — where NO files
+ * were touched — apart from a generic mid-sync filesystem failure, and message
+ * the user accurately (#791 blocker-C).
+ */
+export class ManifestError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'ManifestError';
+  }
+}
+
 export interface FrameworkManifest {
   /** Globs the updater MAY create/overwrite, and prune only when retired. */
   readonly framework: readonly string[];
@@ -49,21 +62,68 @@ export function parseManifest(text: string): FrameworkManifest {
       continue;
     }
     if (line.startsWith('[')) {
-      throw new Error(`Unknown manifest section header on line ${i + 1}: ${line}`);
+      throw new ManifestError(`Unknown manifest section header on line ${i + 1}: ${line}`);
     }
 
     if (section === null) {
-      throw new Error(`Manifest entry before any [section] header on line ${i + 1}: ${line}`);
+      throw new ManifestError(
+        `Manifest entry before any [section] header on line ${i + 1}: ${line}`,
+      );
     }
     (section === 'framework' ? framework : operator).push(line);
   }
 
+  // Fail CLOSED on an empty or comment-only manifest. A manifest with zero
+  // framework-owned globs would make resolveOwnership() return `operator` for
+  // every path: an upgrade would prune nothing and refresh nothing — a silent
+  // no-op indistinguishable from success. Refuse loudly instead, mirroring the
+  // bash reader's `manifest_load` guard so both halves reject it identically (#791 B2).
+  if (framework.length === 0) {
+    throw new ManifestError(
+      'Framework manifest defines no [framework] paths — refusing to proceed (empty or malformed manifest).',
+    );
+  }
+
+  // Fail CLOSED on framework entries that normalize to nothing usable. A manifest
+  // like `[framework]\n/` or `[framework]\n./` passes the length check above but
+  // every entry normalizes to an empty (or bare-dot) glob that matches no real
+  // path — so the compiled framework matcher is empty and every path resolves
+  // `operator`: the same silent no-op as an empty manifest. Require at least one
+  // entry with a real, non-dot character (the bash reader applies the identical
+  // `[^/.]` test, so both halves reject these inputs together — #791 blocker-B).
+  if (!framework.some(isUsableFrameworkGlob)) {
+    throw new ManifestError(
+      'Framework manifest defines no usable [framework] paths (every entry is empty or a bare dot segment) — refusing to proceed (malformed manifest).',
+    );
+  }
+
   return { framework, operator };
 }
 
+/**
+ * A framework glob is usable only if, once normalized, it still contains a
+ * character other than `/` or `.` — i.e. it names a real path segment or a
+ * wildcard. `''`, `/`, `./`, `.`, `..` are all unusable (they compile to a glob
+ * that matches nothing). Kept byte-compatible with the bash `[[ =~ [^/.] ]]`
+ * test so TS and bash accept/reject exactly the same manifests.
+ */
+function isUsableFrameworkGlob(glob: string): boolean {
+  return /[^/.]/.test(normalizeRel(glob));
+}
+
 /** Read and parse the manifest from a framework root directory. */
 export function loadManifest(frameworkRoot: string): FrameworkManifest {
-  const text = readFileSync(`${frameworkRoot}/framework-manifest.txt`, 'utf-8');
+  const file = `${frameworkRoot}/framework-manifest.txt`;
+  let text: string;
+  try {
+    text = readFileSync(file, 'utf-8');
+  } catch (err) {
+    // A missing/unreadable manifest must fail closed with a clear message, not a
+    // raw ENOENT that a caller might mistake for an empty result set (#791 B2/B3).
+    throw new ManifestError(
+      `Cannot read framework manifest at ${file}: ${(err as Error).message} — refusing to sync (fail-closed).`,
+    );
+  }
   return parseManifest(text);
 }
 

packages/mosaic/src/stages/finalize-sync-abort.spec.ts

@@ -0,0 +1,136 @@
+/**
+ * Tests for the framework-sync abort messaging (#791 B2 + blocker-C).
+ *
+ * finalizeStage runs `config.syncFramework()` first, inside a try/catch. If the
+ * sync throws, the wizard must:
+ *   1. NEVER fall through to "Installation complete" — the error is re-raised so
+ *      the process exits non-zero (#791 B2).
+ *   2. Classify the failure so recovery advice is accurate (#791 blocker-C):
+ *        - ManifestError  → a PRE-sync validation abort; nothing was written, so
+ *          the message states "no files were changed".
+ *        - any other error → may surface mid-copy, so the message must NOT claim
+ *          nothing changed; it warns the state "may be partially applied".
+ *
+ * We assert on the spinner's stop() message (the user-visible line) and that the
+ * original error is re-thrown unchanged in both cases.
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { join } from 'node:path';
+import { tmpdir } from 'node:os';
+import type { WizardState } from '../types.js';
+import type { ConfigService } from '../config/config-service.js';
+import { ManifestError } from '../framework/manifest.js';
+
+vi.mock('node:child_process', () => ({
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  spawnSync: vi.fn<any>().mockReturnValue({ status: 0, stdout: '', stderr: '' }),
+}));
+
+vi.mock('../platform/detect.js', () => ({
+  getShellProfilePath: () => null,
+}));
+
+import { finalizeStage } from './finalize.js';
+
+function makeState(mosaicHome: string): WizardState {
+  return {
+    mosaicHome,
+    sourceDir: mosaicHome,
+    mode: 'quick',
+    installAction: 'keep',
+    soul: { agentName: 'TestBot', communicationStyle: 'direct' },
+    user: {},
+    tools: {},
+    runtimes: { detected: [], mcpConfigured: false },
+    selectedSkills: [],
+  };
+}
+
+function buildPrompter() {
+  const stop = vi.fn();
+  const update = vi.fn();
+  const prompter = {
+    intro: vi.fn(),
+    outro: vi.fn(),
+    note: vi.fn(),
+    log: vi.fn(),
+    warn: vi.fn(),
+    text: vi.fn(),
+    confirm: vi.fn(),
+    select: vi.fn(),
+    multiselect: vi.fn(),
+    groupMultiselect: vi.fn(),
+    spinner: vi.fn().mockReturnValue({ update, stop }),
+    separator: vi.fn(),
+  };
+  return { prompter, stop };
+}
+
+function makeConfigService(syncFramework: ConfigService['syncFramework']): ConfigService {
+  return {
+    readSoul: vi.fn().mockResolvedValue({}),
+    readUser: vi.fn().mockResolvedValue({}),
+    readTools: vi.fn().mockResolvedValue({}),
+    writeSoul: vi.fn().mockResolvedValue(undefined),
+    writeUser: vi.fn().mockResolvedValue(undefined),
+    writeTools: vi.fn().mockResolvedValue(undefined),
+    syncFramework,
+    get: vi.fn(),
+    set: vi.fn(),
+    getSection: vi.fn(),
+  } as unknown as ConfigService;
+}
+
+describe('finalizeStage — framework sync abort (#791 B2 + blocker-C)', () => {
+  let tmp: string;
+
+  beforeEach(() => {
+    tmp = mkdtempSync(join(tmpdir(), 'mosaic-sync-abort-'));
+  });
+
+  afterEach(() => {
+    rmSync(tmp, { recursive: true, force: true });
+    vi.clearAllMocks();
+  });
+
+  it('re-throws a ManifestError and reports that no files were changed', async () => {
+    const err = new ManifestError('Framework manifest defines no usable [framework] paths');
+    const { prompter, stop } = buildPrompter();
+    const config = makeConfigService(vi.fn().mockRejectedValue(err));
+
+    await expect(finalizeStage(prompter, makeState(tmp), config)).rejects.toBe(err);
+
+    // The abort message must state nothing was written (pre-sync validation).
+    expect(stop).toHaveBeenCalledWith(expect.stringContaining('no files were changed'));
+    // It must NOT fall through to a success line.
+    expect(stop).not.toHaveBeenCalledWith(expect.stringContaining('Installation complete'));
+  });
+
+  it('re-throws a non-ManifestError and warns the state may be partially applied', async () => {
+    const err = new Error('cp: write error mid-sync (disk full)');
+    const { prompter, stop } = buildPrompter();
+    const config = makeConfigService(vi.fn().mockRejectedValue(err));
+
+    await expect(finalizeStage(prompter, makeState(tmp), config)).rejects.toBe(err);
+
+    // A generic mid-sync failure must NOT claim nothing changed…
+    expect(stop).toHaveBeenCalledWith(expect.stringContaining('may be partially applied'));
+    expect(stop).not.toHaveBeenCalledWith(expect.stringContaining('no files were changed'));
+    expect(stop).not.toHaveBeenCalledWith(expect.stringContaining('Installation complete'));
+  });
+
+  it('does not proceed to config writes when the sync aborts', async () => {
+    const err = new ManifestError('malformed manifest');
+    const { prompter } = buildPrompter();
+    const config = makeConfigService(vi.fn().mockRejectedValue(err));
+
+    await expect(finalizeStage(prompter, makeState(tmp), config)).rejects.toBe(err);
+
+    // writeSoul/writeUser/writeTools are only reached after a successful sync.
+    expect(config.writeSoul).not.toHaveBeenCalled();
+    expect(config.writeUser).not.toHaveBeenCalled();
+    expect(config.writeTools).not.toHaveBeenCalled();
+  });
+});

packages/mosaic/src/stages/finalize.ts

@@ -6,6 +6,7 @@ import type { WizardPrompter } from '../prompter/interface.js';
 import type { ConfigService } from '../config/config-service.js';
 import type { WizardState } from '../types.js';
 import { getShellProfilePath } from '../platform/detect.js';
+import { ManifestError } from '../framework/manifest.js';
 
 function linkRuntimeAssets(mosaicHome: string, skipClaudeHooks: boolean): void {
   const script = join(mosaicHome, 'bin', 'mosaic-link-runtime-assets');
@@ -160,7 +161,26 @@ export async function finalizeStage(
 
   // 1. Sync framework files (before config writes so identity files aren't overwritten)
   spin.update('Syncing framework files...');
-  await config.syncFramework(state.installAction);
+  try {
+    await config.syncFramework(state.installAction);
+  } catch (err) {
+    // Stop the spinner loudly and re-raise so the process exits non-zero — never
+    // fall through to "Installation complete" on an aborted sync (#791 B2).
+    // A ManifestError is a PRE-sync validation abort: the manifest is loaded and
+    // validated before any file is written, so nothing was touched. Any other
+    // error can surface AFTER files were partially copied, so we must NOT claim
+    // "no files were changed" for it — that would misdirect recovery (#791 blocker-C).
+    if (err instanceof ManifestError) {
+      spin.stop(
+        'Framework sync aborted — the framework manifest is missing, empty, or malformed; no files were changed.',
+      );
+    } else {
+      spin.stop(
+        'Framework sync aborted — the update did not complete and may be partially applied; see the error below.',
+      );
+    }
+    throw err;
+  }
 
   // 2. Write config files (after sync so they aren't overwritten by source templates)
   if (state.installAction !== 'keep') {