feat(evidence): verification-evidence ledger mechanizes /ship's IRON LAW

New bin/gstack-evidence: a transparent wrapper that records every verification
run as {ts, label, command, cmd_sha256, exit, duration_s, commit, tree, dirty,
wtree, log_path} in ~/.gstack/projects/<slug>/<branch>-evidence.jsonl, plus a
read-only `check` that grades FRESH/STALE/MISSING per label. "Tests passed"
now binds to the exact working-tree content it ran on (bin/gstack-wtree
fingerprint), so evidence recorded on uncommitted code stays FRESH after the
exact tested content is committed — the /ship Step 5 -> Step 16 case — while
an untracked new source file or any content change invalidates it.

Check semantics: every named label's latest record must be green, within
--max-age, matching --expect-cmd's hash when given, and fingerprint-identical
(or diff confined to --allow-paths — mechanizing Step 16's existing "CHANGELOG
edits don't count" carve-out). No --any mode: a green lane can never mask a
red sibling. Any git failure inside check (gc'd tree object, not a repo)
degrades to STALE/MISSING, never an error into the calling skill flow.

Transparency invariant (load-bearing, test-pinned): the child's exit code is
ALWAYS the wrapper's exit code; ledger/log/redact failures are stderr
warnings. Logs are per-run (0600, exclusive-open, 2MB truncation marker,
30-day opportunistic prune) — no more shared /tmp collisions between
concurrent ships. Command strings are redact-scanned before recording (HIGH
credential -> stored redacted). Machine-local by design: neither ledger nor
logs brain-sync.

Wired: ship Step 5 lanes run wrapped (per-lane labels), ship Step 16 and
land-and-deploy 3.5b check the ledger first and cite FRESH evidence instead of
re-running; a failed CHECK never blocks (run live), a failed RUN does.
test/evidence.test.ts: 21 tests incl. the keystone dirty-record -> commit ->
FRESH case.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ship/SKILL.md

@@ -1280,9 +1280,24 @@ EOF
 
 **IRON LAW: NO COMPLETION CLAIMS WITHOUT FRESH VERIFICATION EVIDENCE.**
 
+The evidence ledger is the mechanical arm of this law. Check it FIRST:
+
+```bash
+~/.claude/skills/gstack/bin/gstack-evidence check --label tests --label vitest --max-age 24 --allow-paths CHANGELOG.md,VERSION,package.json
+```
+
+- **Every line FRESH (exit 0):** the recorded runs were green and the working-tree
+  content is identical to what was tested, modulo the allow-listed release files
+  (this mechanizes the "CHANGELOG edits don't count" rule — VERSION/CHANGELOG
+  commits between Step 5 and here don't invalidate the run). Cite the evidence
+  lines (label, exit, ts, log path) as the verification evidence and continue.
+- **Any STALE/MISSING (exit non-zero):** run live, wrapped, so the fresh run is
+  recorded: `~/.claude/skills/gstack/bin/gstack-evidence run --label <lane> -- '<command>'`.
+  The check is an advisory guardrail — a failed CHECK never blocks; a failed RUN does.
+
 Before pushing, re-verify if code changed during Steps 4-6:
 
-1. **Test verification:** If ANY code changed after Step 5's test run (fixes from review findings, CHANGELOG edits don't count), re-run the test suite. Paste fresh output. Stale output from Step 5 is NOT acceptable.
+1. **Test verification:** If ANY code changed after Step 5's test run (fixes from review findings, CHANGELOG edits don't count), re-run the test suite. The evidence check above IS this rule, mechanized — trust FRESH, re-run on STALE. Paste fresh output when you re-run. Stale output from Step 5 with changed content is NOT acceptable.
 
 2. **Build verification:** If the project has a build step, run it. Paste output.
 

ship/SKILL.md.tmpl

@@ -375,9 +375,24 @@ EOF
 
 **IRON LAW: NO COMPLETION CLAIMS WITHOUT FRESH VERIFICATION EVIDENCE.**
 
+The evidence ledger is the mechanical arm of this law. Check it FIRST:
+
+```bash
+~/.claude/skills/gstack/bin/gstack-evidence check --label tests --label vitest --max-age 24 --allow-paths CHANGELOG.md,VERSION,package.json
+```
+
+- **Every line FRESH (exit 0):** the recorded runs were green and the working-tree
+  content is identical to what was tested, modulo the allow-listed release files
+  (this mechanizes the "CHANGELOG edits don't count" rule — VERSION/CHANGELOG
+  commits between Step 5 and here don't invalidate the run). Cite the evidence
+  lines (label, exit, ts, log path) as the verification evidence and continue.
+- **Any STALE/MISSING (exit non-zero):** run live, wrapped, so the fresh run is
+  recorded: `~/.claude/skills/gstack/bin/gstack-evidence run --label <lane> -- '<command>'`.
+  The check is an advisory guardrail — a failed CHECK never blocks; a failed RUN does.
+
 Before pushing, re-verify if code changed during Steps 4-6:
 
-1. **Test verification:** If ANY code changed after Step 5's test run (fixes from review findings, CHANGELOG edits don't count), re-run the test suite. Paste fresh output. Stale output from Step 5 is NOT acceptable.
+1. **Test verification:** If ANY code changed after Step 5's test run (fixes from review findings, CHANGELOG edits don't count), re-run the test suite. The evidence check above IS this rule, mechanized — trust FRESH, re-run on STALE. Paste fresh output when you re-run. Stale output from Step 5 with changed content is NOT acceptable.
 
 2. **Build verification:** If the project has a build step, run it. Paste output.
 

ship/sections/tests.md

@@ -195,15 +195,22 @@ Only commit if there are changes. Stage all bootstrap files (config, test direct
 `db:test:prepare` internally, which loads the schema into the correct lane database.
 Running bare test migrations without INSTANCE hits an orphan DB and corrupts structure.sql.
 
-Run both test suites in parallel:
+Run both test suites in parallel, each wrapped in the evidence ledger. The
+wrapper is transparent (streams output live, exit code passes through) and
+records `{command, exit, working-tree fingerprint, log path}` to
+`~/.gstack/projects/<slug>/<branch>-evidence.jsonl` — Step 16 cites this
+record instead of re-running when the content hasn't changed:
 
 ```bash
-bin/test-lane 2>&1 | tee /tmp/ship_tests.txt &
-npm run test 2>&1 | tee /tmp/ship_vitest.txt &
+~/.claude/skills/gstack/bin/gstack-evidence run --label tests -- 'bin/test-lane 2>&1' &
+~/.claude/skills/gstack/bin/gstack-evidence run --label vitest -- 'npm run test 2>&1' &
 wait
 ```
 
-After both complete, read the output files and check pass/fail.
+After both complete, check the `gstack-evidence: recorded label=... exit=...
+log=...` summary lines — each carries the lane's exit code and a per-run log
+file (no shared /tmp collisions between concurrent ships). Read the log files
+for failure detail.
 
 **If any test fails:** Do NOT immediately stop. Apply the Test Failure Ownership Triage:
 

ship/sections/tests.md.tmpl

@@ -10,15 +10,22 @@
 `db:test:prepare` internally, which loads the schema into the correct lane database.
 Running bare test migrations without INSTANCE hits an orphan DB and corrupts structure.sql.
 
-Run both test suites in parallel:
+Run both test suites in parallel, each wrapped in the evidence ledger. The
+wrapper is transparent (streams output live, exit code passes through) and
+records `{command, exit, working-tree fingerprint, log path}` to
+`~/.gstack/projects/<slug>/<branch>-evidence.jsonl` — Step 16 cites this
+record instead of re-running when the content hasn't changed:
 
 ```bash
-bin/test-lane 2>&1 | tee /tmp/ship_tests.txt &
-npm run test 2>&1 | tee /tmp/ship_vitest.txt &
+~/.claude/skills/gstack/bin/gstack-evidence run --label tests -- 'bin/test-lane 2>&1' &
+~/.claude/skills/gstack/bin/gstack-evidence run --label vitest -- 'npm run test 2>&1' &
 wait
 ```
 
-After both complete, read the output files and check pass/fail.
+After both complete, check the `gstack-evidence: recorded label=... exit=...
+log=...` summary lines — each carries the lane's exit code and a per-run log
+file (no shared /tmp collisions between concurrent ships). Read the log files
+for failure detail.
 
 **If any test fails:** Do NOT immediately stop. Apply the Test Failure Ownership Triage: