fix(installer): fail closed on test enumeration errors

docs/reports/verification/1050-c1-fix-round/01-pre-fix-positive-control.log

@@ -0,0 +1,13 @@
+[test] --next fast path pins resolved package versions
+[test] fast path failure falls back to source build
+[test] source-build failure is fatal and restores the pre-install prefix
+[test] corrupt source archive is fatal and restores the pre-install prefix
+[test] source archive with multiple extracted roots fails instead of selecting by find order
+[test] --dev source install does not require registry version resolution
+[test] explicit --ref keeps source lane and avoids @next lookup
+[test] --check --next rejects mismatched prerelease pipeline suffixes
+[test] full framework path receives P3 absolute CLI without relying on PATH
+[test] captured diagnostics redact seeded credential canary everywhere
+[test] framework nested capture redacts the same canary and URL variants
+[test] real P2-P8 actions run under fault injection and restore actual surfaces
+P2 left an in-progress transaction

docs/reports/verification/1050-c1-fix-round/02-pre-fix-permission-failure-attack.log

@@ -0,0 +1,14 @@
+[test] --next fast path pins resolved package versions
+[test] fast path failure falls back to source build
+[test] source-build failure is fatal and restores the pre-install prefix
+[test] corrupt source archive is fatal and restores the pre-install prefix
+[test] source archive with multiple extracted roots fails instead of selecting by find order
+[test] --dev source install does not require registry version resolution
+[test] explicit --ref keeps source lane and avoids @next lookup
+[test] --check --next rejects mismatched prerelease pipeline suffixes
+[test] full framework path receives P3 absolute CLI without relying on PATH
+[test] captured diagnostics redact seeded credential canary everywhere
+[test] framework nested capture redacts the same canary and URL variants
+[test] real P2-P8 actions run under fault injection and restore actual surfaces
+[test] stale projection is preserved while the real fault path acquires a free OS lock
+[test] installer next lane tests passed

docs/reports/verification/1050-c1-fix-round/03-regression-test-red.log

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+[test] enumeration failure cannot mask a planted in-progress transaction
+[test] FAIL: planted in-progress transaction plus failed enumeration passed the full suite

docs/reports/verification/1050-c1-fix-round/04-post-fix-permission-failure-attack.log

@@ -0,0 +1,14 @@
+[test] --next fast path pins resolved package versions
+[test] fast path failure falls back to source build
+[test] source-build failure is fatal and restores the pre-install prefix
+[test] corrupt source archive is fatal and restores the pre-install prefix
+[test] source archive with multiple extracted roots fails instead of selecting by find order
+[test] --dev source install does not require registry version resolution
+[test] explicit --ref keeps source lane and avoids @next lookup
+[test] --check --next rejects mismatched prerelease pipeline suffixes
+[test] full framework path receives P3 absolute CLI without relying on PATH
+[test] captured diagnostics redact seeded credential canary everywhere
+[test] framework nested capture redacts the same canary and URL variants
+[test] real P2-P8 actions run under fault injection and restore actual surfaces
+find: ‘/tmp/mosaic-next-install-test-hqL7U0/fault-P2/blocked’: Permission denied
+[test] ERROR: P2 fault-state enumeration failed

docs/reports/verification/1050-c1-fix-round/README.md

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+# #1050 C1 fix-round verification
+
+Frozen reviewed head before remediation: `378bc1afe3bc485adb8614897d66c5edccd4a527`.
+
+Status: **believed-fixed, pending jarvis validation**. PR #1054 is not self-merged and issue #1050 remains open.
+
+## Blocker B — fail-closed test enumeration
+
+The RED-first control used a real filesystem permission failure, not binary shadowing or PATH interception.
+
+1. A planted `{"status":"in-progress"}` file in a readable P2 fault tree made the complete real walk fail the frozen suite at `P2 left an in-progress transaction` (`01-pre-fix-positive-control.log`, exit 1).
+2. The same planted defect beneath a target-owned mode-0100 directory made real `find` report a permission failure. The frozen suite erased the producer failure and exited 0 with `installer next lane tests passed` (`02-pre-fix-permission-failure-attack.log`).
+3. The committed regression control initially failed because the child full-suite attack still exited 0 (`03-regression-test-red.log`).
+4. After remediation, the same child full-suite input exits 1 and names `[test] ERROR: P2 fault-state enumeration failed` (`04-post-fix-permission-failure-attack.log`). The ordinary full suite remains green.
+
+`tools/test-enumeration-assertions.sh` now captures each complete NUL-delimited population and checks the producer status before asserting absence. Content checks inspect the captured population and distinguish “no match” from a read error. The shared fail-closed implementation covers:
+
+- `tools/install-next-lane.test.sh`: redacted staging-file cleanup and fault-state transaction scan;
+- `tools/verified-installer-fetch.test.sh`: temporary-download cleanup;
+- `tools/install-state-machine.test.sh`: symlink-target non-mutation;
+- `docs/reports/verification/1050-b8-redaction-control/positive-control.test.sh`: both copied counterparts.
+
+No assertion was loosened. A1, A2, upgrade-guard, source-root, the species-2 sweep, #869, and expected-RED verdict rows remain outside this remediation.
+
+## Blocker A — installer digest
+
+The stale sidecar value was replaced with the exact `sha256sum` record for `tools/install.sh`:
+
+```text
+e59cb441a2f37ae9150f8eae470238e9d858a1816df93343d9784a6796676096  install.sh
+```
+
+Local `sha256sum -c tools/install.sh.sha256` and the workflow's exact expected/actual equality both pass. The immutable provider-fetch arm at the new `${CI_COMMIT_SHA}` is recorded in the freeze artifact after push; local equality alone is not treated as sufficient evidence.

docs/reports/verification/1050-c1-fix-round/documentation-checklist.md

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+# Documentation completion checklist — #1050 C1 fix round
+
+## Required artifacts
+
+- [x] `docs/PRD.md` exists; #1050 C1 requirements remain current and unchanged.
+- [x] User guide: not applicable; no user-facing installer behavior changed.
+- [x] Admin guide: not applicable; no operator procedure or deployment behavior changed.
+- [x] Developer guide: existing `docs/guides/installer-state-machine.md` already defines the fail-closed and immutable-remote contracts; this round adds verification evidence without changing the contract.
+- [x] OpenAPI and endpoint index: not applicable; no API changed.
+- [x] Sitemap: not applicable; no navigation changed.
+
+## API and structural coverage
+
+- [x] API schema/auth/error coverage: not applicable; no endpoint changed.
+- [x] Guide book indexes: not applicable; no guide page was added or moved.
+- [x] Root hygiene preserved; all new artifacts are under `docs/reports/verification/1050-c1-fix-round/` and the active scratchpad remains under `docs/scratchpads/`.
+
+## Review and publishing
+
+- [x] Verification documentation is in the same logical change set as the shell-test remediation.
+- [x] Independent code and security reviews found no documentation blocker.
+- [x] Canonical evidence remains in-repo. No external publishing action was requested or performed.