framework: port the credential-helper regression suite (byte-faithful from brain 15f6979a; verified green from the stack tree)

(cherry picked from commit 62b163a254)

packages/mosaic/framework/tools/git/test-git-credential-mosaic.sh

@@ -34,20 +34,23 @@ REPO_DIR="$WORK_DIR/repo"
 BRAIN_DIR="$WORK_DIR/brain"
 SPOOL_DIR="$WORK_DIR/spool"
 SVC_STORE="$FAKE_HOME/.config/mosaic/secrets/gitea-tokens"
-# Mirror the real deployed layout (~/.config/mosaic/tools/{git,_lib}/) under the
+# Mirror the real deployed layout (~/.mosaic/tools/{git,_lib}/) under the
 # fake HOME: git-credential-mosaic resolves its credentials.sh sibling via a
 # script-relative path (BASH_SOURCE), so the copy must live next to a stubbed
 # _lib/credentials.sh, not the real one, to keep this test hermetic.
-HELPER="$FAKE_HOME/.config/mosaic/tools/git/git-credential-mosaic"
+HELPER="$FAKE_HOME/.mosaic/tools/git/git-credential-mosaic"
+IMPL="$FAKE_HOME/.mosaic/tools/git/git-credential-mosaic.impl"
 
 rm -rf "$WORK_DIR"
 mkdir -p "$SVC_STORE" \
-         "$FAKE_HOME/.config/mosaic/tools/git" \
+         "$FAKE_HOME/.mosaic/tools/git" \
-         "$FAKE_HOME/.config/mosaic/tools/_lib" \
+         "$FAKE_HOME/.mosaic/tools/_lib" \
          "$REPO_DIR" "$BRAIN_DIR"
 
 cp "$SCRIPT_DIR/git-credential-mosaic" "$HELPER"
 chmod +x "$HELPER"
+cp "$SCRIPT_DIR/git-credential-mosaic.impl" "$IMPL"
+chmod +x "$IMPL"
 
 git -C "$REPO_DIR" init -q
 git -C "$REPO_DIR" config user.email "[email protected]"
@@ -55,7 +58,7 @@ git -C "$REPO_DIR" config user.name "Test"
 
 # Fake shared-account credential loader — stands in for
 # tools/_lib/credentials.sh's load_credentials(), scoped to this test only.
-cat > "$FAKE_HOME/.config/mosaic/tools/_lib/credentials.sh" <<'SH'
+cat > "$FAKE_HOME/.mosaic/tools/_lib/credentials.sh" <<'SH'
 load_credentials() {
   case "$1" in
     gitea-mosaicstack) GITEA_URL="https://git.mosaicstack.dev"; GITEA_TOKEN="shared-mosaicstack-token"; export GITEA_URL GITEA_TOKEN; return 0 ;;
@@ -82,7 +85,7 @@ run_helper() {
   (
     cd "$REPO_DIR"
     env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" "$@" \
-      bash "$HELPER" get <<EOF
+      "$HELPER" get <<EOF
 host=$host
 username=$username_in
 
@@ -90,6 +93,80 @@ EOF
   )
 }
 
+# ── Lineage harness (rev-code-02 F1/F2 rework) ─────────────────────────────
+# Establishes a seat CALLER the way production does — frozen into an
+# ancestor's exec environment — instead of injecting MOSAIC_AGENT_NAME into
+# the helper's own env. Two scripts are generated into WORK_DIR:
+#
+#   lineage-root.sh  (pid A): invoked with a fence marker and NO agent name.
+#       With a non-empty caller arg it forks the carrier (pid C); with an
+#       empty caller it forks the helper directly (deterministic anonymous
+#       lineage even when the suite itself runs inside a seat).
+#   lineage-carrier.sh (pid C): MOSAIC_AGENT_NAME=<caller> frozen at exec;
+#       forks the helper (pid D) with a fully controlled env.
+#
+# The helper's walk then sees exactly: self -> C(caller) or D-direct ->
+# A(fence, empty name -> stop). EXTRA assignments ride pid D's environment
+# (that is where a rewrite would live — which is the point of the F1 arms).
+cat > "$WORK_DIR/lineage-root.sh" <<'LINROOT'
+#!/usr/bin/env bash
+# pid A — lineage root. Args: <caller> <carrier-script> <helper> <spool>
+# <brain> <repo> [extra KEY=VALUE...]
+set -u
+caller="$1"; carrier="$2"; helper="$3"; spool="$4"; brain="$5"; repo="$6"; shift 6
+if [ -n "$caller" ]; then
+  env MOSAIC_AGENT_NAME="$caller" PATH="$PATH" HOME="$HOME" \
+    bash "$carrier" "$helper" "$spool" "$brain" "$repo" "$@"
+else
+  env -i HOME="$HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$spool" \
+       MOSAIC_BRAIN_HOME="$brain" "$@" "$helper" get
+fi
+LINROOT
+cat > "$WORK_DIR/lineage-carrier.sh" <<'LINCARR'
+#!/usr/bin/env bash
+# pid C — the caller's frozen environment. Forks the helper (pid D).
+set -u
+helper="$1"; spool="$2"; brain="$3"; repo="$4"; shift 4
+cd "$repo"
+env -i HOME="$HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$spool" \
+     MOSAIC_BRAIN_HOME="$brain" "$@" "$helper" get
+LINCARR
+chmod +x "$WORK_DIR/lineage-root.sh" "$WORK_DIR/lineage-carrier.sh"
+
+run_lineage() {
+  # run_lineage <caller|empty-for-anonymous> [helper-env KEY=VALUE...]
+  local caller="$1"; shift
+  printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+    env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_LINEAGE_FENCE=1 \
+      bash "$WORK_DIR/lineage-root.sh" "$caller" "$WORK_DIR/lineage-carrier.sh" \
+      "$HELPER" "$SPOOL_DIR" "$BRAIN_DIR" "$REPO_DIR" "$@"
+}
+
+assert_refused_lineage() {
+  # assert_refused_lineage <desc> <caller> <want-reason> [helper-env...]
+  local desc="$1" caller="$2" want="$3"; shift 3
+  local stderr_file="$WORK_DIR/stderr-lin.tmp" rc stdout
+  : > "$stderr_file"
+  set +e
+  stdout=$(run_lineage "$caller" "$@" 2>"$stderr_file")
+  rc=$?
+  set -e
+  local stderr; stderr=$(cat "$stderr_file")
+  if [[ "$rc" -eq 0 ]]; then
+    echo "FAIL: $desc — expected nonzero exit, got 0 (stdout='$stdout')" >&2; fail=1
+  fi
+  if [[ -n "$stdout" ]]; then
+    echo "FAIL: $desc — expected empty stdout, got '$stdout'" >&2; fail=1
+  fi
+  if [[ -n "$want" && "$stderr" != *"$want"* ]]; then
+    echo "FAIL: $desc — stderr lacks '$want':" >&2; echo "$stderr" >&2; fail=1
+  fi
+  if [[ "$stdout$stderr" == *"seatG-slot-token"* || "$stdout$stderr" == *"seatE-slot-token"* \
+     || "$stdout$stderr" == *"shared-mosaicstack-token"* || "$stdout$stderr" == *"shared-usc-token"* ]]; then
+    echo "FAIL: $desc — a slot or shared token VALUE appeared in output" >&2; fail=1
+  fi
+}
+
 # A refusal must be observable in four independent ways: nonzero exit, EMPTY
 # stdout, a stderr diagnostic naming the identity and host, and — the assertion
 # that actually catches a regression to the old behavior — NO shared token value
@@ -222,7 +299,10 @@ fi
 # ---------------------------------------------------------------------------
 mkdir -p "$BRAIN_DIR/fleet/agents/seatE/secrets"
 echo -n "seatE-slot-token" > "$BRAIN_DIR/fleet/agents/seatE/secrets/gitea-mosaicstack-seatE.token"
-out=$(run_helper "git.mosaicstack.dev" "seatE" MOSAIC_BRAIN_HOME="$BRAIN_DIR")
+chmod 600 "$BRAIN_DIR/fleet/agents/seatE/secrets/gitea-mosaicstack-seatE.token"
+# Seat arms run through the lineage harness below (rev-code-02 F1/F2 rework):
+# a seat caller must be established by ancestry, not by the helper's own env.
+out=$(run_lineage seatE MOSAIC_AGENT_NAME=seatE MOSAIC_GIT_IDENTITY=seatE)
 assert_eq "seat reads its own slot: username" "username=seatE" "$(echo "$out" | grep '^username=')"
 assert_eq "seat reads its own slot: password" "password=seatE-slot-token" "$(echo "$out" | grep '^password=')"
 
@@ -236,8 +316,8 @@ assert_eq "seat reads its own slot: password" "password=seatE-slot-token" "$(ech
 # ---------------------------------------------------------------------------
 mkdir -p "$BRAIN_DIR/fleet/agents/seatF/secrets"
 echo -n "seatF-SERVICE-STORE-token" > "$SVC_STORE/gitea-mosaicstack-seatF.token"
-assert_fail_closed "seat with empty slot does NOT fall back to the framework store" \
+assert_refused_lineage "seat with empty slot does NOT fall back to the framework store" \
-  "git.mosaicstack.dev" "seatF" "fleet/agents/seatF/secrets" MOSAIC_BRAIN_HOME="$BRAIN_DIR"
+  seatF no-token-for-identity MOSAIC_AGENT_NAME=seatF MOSAIC_GIT_IDENTITY=seatF
 : > "$WORK_DIR/stderr.tmp"
 set +e
 xstore_out=$(run_helper "git.mosaicstack.dev" "seatF" MOSAIC_BRAIN_HOME="$BRAIN_DIR" 2>"$WORK_DIR/stderr.tmp")
@@ -288,7 +368,7 @@ assert_eq "unknown host on a fleet host: still passthrough, not a refusal" "" "$
 # 13. Non-"get" verb (store/erase) -> exit 0, no output (git-credential
 #     protocol: this helper only implements get).
 # ---------------------------------------------------------------------------
-store_out=$(cd "$REPO_DIR" && env -i HOME="$FAKE_HOME" PATH="$PATH" bash "$HELPER" store <<EOF
+store_out=$(cd "$REPO_DIR" && env -i HOME="$FAKE_HOME" PATH="$PATH" "$HELPER" store <<EOF
 host=git.mosaicstack.dev
 username=no-such-agent
 password=whatever
@@ -310,7 +390,7 @@ hostile_spool="$WORK_DIR/spool-hostile"
   cd "$hostile_dir"
   env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$hostile_spool" \
     MOSAIC_GIT_IDENTITY=no-such-agent \
-    bash "$HELPER" get <<EOF >/dev/null 2>&1
+    "$HELPER" get <<EOF >/dev/null 2>&1
 host=git.mosaicstack.dev
 username=no-such-agent
 
@@ -349,7 +429,7 @@ nospool_err=$(
   cd "$REPO_DIR"
   env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$unwritable_spool" \
     MOSAIC_GIT_IDENTITY=no-such-agent \
-    bash "$HELPER" get <<EOF 2>&1 >/dev/null
+    "$HELPER" get <<EOF 2>&1 >/dev/null
 host=git.mosaicstack.dev
 username=no-such-agent
 
@@ -365,6 +445,193 @@ if [[ "$nospool_err" != *"NOT WRITTEN"* ]]; then
   fail=1
 fi
 
+# ---------------------------------------------------------------------------
+# 11. P5-RM-006 (+r1 rework) — caller identity from exec-frozen ancestry.
+#    A seat caller is established by lineage, not by the helper's own env;
+#    disagreement anywhere in the lineage is a rewrite and refuses; an
+#    anonymous caller resolves NOTHING on a fleet host (seat or service);
+#    a loose seat-slot mode refuses. Enforcement-removal red control at 11h.
+# ---------------------------------------------------------------------------
+mkdir -p "$BRAIN_DIR/fleet/agents/seatG/secrets"
+echo -n "seatG-slot-token" > "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+chmod 600 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+
+# 11a. Cross-seat negative (lineage seatE, env ident=seatG): still refused.
+assert_refused_lineage "seat cannot override identity to another seat's slot" \
+  seatE cross-seat-identity-refused MOSAIC_GIT_IDENTITY=seatG
+
+# 11b. Seat asking for a SERVICE identity: cross-seat territory.
+assert_refused_lineage "seat cannot resolve a service identity either" \
+  seatE cross-seat-identity-refused MOSAIC_GIT_IDENTITY=agentA
+
+# 11c. Anonymous caller asking for a SEAT slot: refused (T94 jarvis@ class).
+assert_refused_lineage "anonymous caller cannot resolve a seat slot on a fleet host" \
+  "" anonymous-credential-refused MOSAIC_GIT_IDENTITY=seatG
+
+# 11d. Anonymous caller asking for a SERVICE identity: ALSO refused
+#     (rev-code-02 F2 — credentialed services are seats; the legacy store is
+#     not anonymously reachable on fleet hosts).
+assert_refused_lineage "anonymous caller cannot resolve a legacy service credential either" \
+  "" anonymous-credential-refused MOSAIC_GIT_IDENTITY=agentA
+
+# 11e. Slot permissions: a group-readable slot is refused; mode restored -> serves.
+chmod 644 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+assert_refused_lineage "loose slot mode is refused" \
+  seatG slot-permission-violation MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG
+chmod 600 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+out=$(run_lineage seatG MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG)
+assert_eq "mode restored to 600: seatG serves again" "password=seatG-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11f. rev-code-02 F1 repro: dual-variable override (caller lineage seatE,
+#     helper env carrying MOSAIC_AGENT_NAME=seatG AND MOSAIC_GIT_IDENTITY=seatG).
+assert_refused_lineage "F1: dual MOSAIC_AGENT_NAME+MOSAIC_GIT_IDENTITY override refused" \
+  seatE caller-identity-spoof-refused MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG
+
+# 11g. Stripped lineage still serves the rightful seat: caller frozen at the
+#     ancestor, helper env clean (self empty), own ident.
+out=$(run_lineage seatE MOSAIC_GIT_IDENTITY=seatE)
+assert_eq "lineage consensus with stripped self still serves the owning seat" \
+  "password=seatE-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11h. RED CONTROL: delete the ancestry binding between markers from a copy
+#     of the IMPLEMENTATION (run directly with the clean marker — a red control
+#     measures the binding itself, deliberately not through the wrapper);
+#     the F1 dual-override request must then RESOLVE seatG's token — the
+#     exact measured failure — proving the binding is the enforcement.
+RED_HELPER="$WORK_DIR/red/git-credential-mosaic.impl"
+mkdir -p "$WORK_DIR/red"
+sed '/P5-RM-006r1 ancestry binding begin/,/P5-RM-006r1 ancestry binding end/d' "$IMPL" > "$RED_HELPER"
+chmod +x "$RED_HELPER"
+if cmp -s "$IMPL" "$RED_HELPER"; then
+  echo "FAIL: red control is vacuous — marker deletion removed nothing" >&2
+  fail=1
+fi
+set +e
+red_out=$(printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_LINEAGE_FENCE=1 \
+    bash "$WORK_DIR/lineage-root.sh" seatE "$WORK_DIR/lineage-carrier.sh" \
+      "$RED_HELPER" "$SPOOL_DIR" "$BRAIN_DIR" "$REPO_DIR" \
+      _MOSAIC_HELPER_CLEAN=1 MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG 2>/dev/null)
+set -e
+if [[ "$(echo "$red_out" | grep '^password=')" != "password=seatG-slot-token" ]]; then
+  echo "FAIL: red control — with the binding removed, the F1 dual-override should have resolved seatG's token, got: $red_out" >&2
+  fail=1
+else
+  echo "ok: red control — binding removed -> F1 dual-override resolves the victim token (the binding is the enforcement)"
+fi
+
+# 11h2. rev-code-02 R1 F1: PATH-shadowed tr/sed/head/grep must not forge the
+#      ancestry. The dual-override request runs with a hostile PATH whose
+#      utilities claim the victim name for every /proc read; the walker uses
+#      only bash builtins, so the shadows never execute and the refusal holds.
+HOSTILE_BIN="$WORK_DIR/hostile-bin"
+mkdir -p "$HOSTILE_BIN"
+for tool in tr sed head grep cat stat; do
+  printf '#!/usr/bin/env bash\ncat >/dev/null\necho "MOSAIC_AGENT_NAME=seatG"\nexit 0\n' > "$HOSTILE_BIN/$tool"
+  chmod +x "$HOSTILE_BIN/$tool"
+done
+assert_refused_lineage "F1-R1: hostile PATH utilities cannot forge ancestry (dual override still refused)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG PATH="$HOSTILE_BIN:$PATH"
+
+# 11i. Service automation integration arm (rev-code-02 R2 bar): a SERVICE
+#      seat bound by lineage resolves its own slot — the brain-git-sync shape.
+mkdir -p "$BRAIN_DIR/fleet/agents/svc-fixture/secrets"
+echo -n "svc-fixture-slot-token" > "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+chmod 600 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+out=$(run_lineage svc-fixture MOSAIC_AGENT_NAME=svc-fixture MOSAIC_GIT_IDENTITY=svc-fixture)
+assert_eq "service automation with bound seat lineage resolves its own slot" \
+  "password=svc-fixture-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11j. rev-code-02 R3 B1: BASH_ENV shaping. A read() shadow defined through
+#      BASH_ENV must be refused before any resolution — the guard scrubs and
+#      refuses with bash-environment-injection-refused.
+INJ_SH="$WORK_DIR/inj-read.sh"
+printf 'read() { builtin read -r _x || return 0; printf "MOSAIC_AGENT_NAME=seatG\\n"; return 0; }\n' > "$INJ_SH"
+assert_refused_lineage "F1-R3: BASH_ENV read() shadow is dropped at the wrapper boundary (identity gate governs)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_SH"
+
+# 11k. rev-code-02 R3 B1: exported functions (BASH_FUNC_* import) refused too.
+assert_refused_lineage "F1-R3: exported BASH_FUNC_* import never crosses the wrapper boundary (identity gate governs)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG \
+  'BASH_FUNC_read%%=() { builtin read -r _x || return 0; printf "MOSAIC_AGENT_NAME=seatG\\n"; return 0; }'
+
+# 11l. rev-code-02 R3 B2: hostile stat cannot launder a loose slot. Own-slot
+#      lineage (legit caller), 0644 slot, PATH-shadowed stat reporting 600 —
+#      mode inspection must come from the trusted PATH and still refuse.
+chmod 644 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+printf '#!/usr/bin/env bash\necho 600\n' > "$HOSTILE_BIN/stat"
+assert_refused_lineage "F2-R3: hostile stat cannot make a 0644 slot pass as 600 (own-slot path)" \
+  svc-fixture slot-permission-violation \
+  MOSAIC_AGENT_NAME=svc-fixture MOSAIC_GIT_IDENTITY=svc-fixture PATH="$HOSTILE_BIN:$PATH"
+chmod 600 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+
+# 11m. rev-code-02 R3 probe 1 through the PRODUCTION ENTRYPOINT: BASH_ENV
+#      defines unset()/exit() no-ops (defeating in-bash scrub/termination).
+#      The python wrapper never passes BASH_ENV across the boundary, so the
+#      implementation cannot be shaped and the dual override still refuses.
+INJ_P1="$WORK_DIR/inj-probe1.sh"
+cat > "$INJ_P1" <<'P1'
+unset() { return 0; }
+exit() { return 0; }
+read() { builtin read -r _x || return 0; printf 'MOSAIC_AGENT_NAME=seatG\n'; return 0; }
+P1
+assert_refused_lineage "F1-R4 probe1: BASH_ENV unset/exit no-ops cannot shape the helper (wrapper boundary)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_P1"
+
+# 11n. rev-code-02 R3 probe 2 through the PRODUCTION ENTRYPOINT: declare()
+#      hides imported functions, unsets the marker, printf() forges the
+#      ancestry. Dropped at the wrapper boundary; refusal holds.
+INJ_P2="$WORK_DIR/inj-probe2.sh"
+cat > "$INJ_P2" <<'P2'
+declare() { return 0; }
+printf() { builtin printf '%s' "MOSAIC_AGENT_NAME=seatG"; return 0; }
+read() { builtin read -r _x || return 0; printf 'MOSAIC_AGENT_NAME=seatG\n'; return 0; }
+P2
+assert_refused_lineage "F1-R4 probe2: declare-hide + printf-forge cannot shape the helper (wrapper boundary)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_P2"
+
+# 11o. RED CONTROL for the wrapper boundary (enforcement-removal): invoke the
+#      IMPLEMENTATION directly, bypassing the wrapper, with the PROBE-1 shape
+#      (unset/exit no-ops) and a forged clean marker — exactly the falsified
+#      in-bash world the reviewer measured: the refusal prints, exit is
+#      no-oped, execution continues, and the forged ancestry SERVES seatG.
+#      The wrapper boundary is the enforcement; this arm proves it bites.
+set +e
+bypass_out=$(cd "$REPO_DIR" && printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" \
+    MOSAIC_BRAIN_HOME="$BRAIN_DIR" _MOSAIC_HELPER_CLEAN=1 BASH_ENV="$INJ_P1" \
+    MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG \
+    bash "$IMPL" get 2>/dev/null)
+set -e
+if [[ "$(echo "$bypass_out" | grep -c '^password=')" -lt 1 ]]; then
+  echo "FAIL: wrapper red control — direct shaped .impl should have served (wrapper is the enforcement), got: $bypass_out" >&2
+  fail=1
+else
+  echo "ok: red control — wrapper bypassed + probe1 shape serves (the wrapper boundary is the enforcement)"
+fi
+
+# 11p. Direct .impl invocation WITHOUT the clean marker: refused by the
+#      implementation's own entrypoint assert.
+set +e
+direct_out=$(cd "$REPO_DIR" && printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" \
+    MOSAIC_BRAIN_HOME="$BRAIN_DIR" MOSAIC_GIT_IDENTITY=seatE \
+    bash "$IMPL" get 2>"$WORK_DIR/stderr-direct.tmp")
+direct_rc=$?
+set -e
+if [[ "$direct_rc" -eq 0 || -n "$direct_out" ]]; then
+  echo "FAIL: direct .impl without marker must refuse (got rc=$direct_rc out='$direct_out')" >&2
+  fail=1
+elif ! grep -q 'direct-entrypoint-refused' "$WORK_DIR/stderr-direct.tmp"; then
+  echo "FAIL: direct .impl refusal lacks direct-entrypoint-refused" >&2
+  fail=1
+fi
+
 if [[ "$fail" -eq 0 ]]; then
   echo "git-credential-mosaic identity resolution regression passed"
 fi