HAC-336: assemble the final cut, and gate it against the evidence it shows

.github/workflows/ci.yml

@@ -933,3 +933,79 @@ jobs:
             echo "stale, re-run \`pnpm run package:build\`; if a capture is stale, re-run"
             echo "\`pnpm run package:capture\` against the merged cockpit."
           } >> "$GITHUB_STEP_SUMMARY"
+
+  # The final cut. This job does not encode anything: `ffmpeg` is not on the
+  # runner and adding it would make the gate depend on a tool that can be absent,
+  # which is how a gate becomes a comment. `verify-film.mjs` reads the committed
+  # MP4's own boxes instead.
+  final-media-gate:
+    name: Final media gate
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22.19.0'
+          cache: pnpm
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile --ignore-scripts
+
+      - name: Verify the assembled cut
+        run: pnpm run check:film
+
+      # The boards, the captions and the two manifests are pure functions of the
+      # cut and the frozen evidence. The frames are not — resvg's text
+      # rasterisation is not byte-identical across hosts — so they are bound by
+      # source digest rather than by rebuild, exactly as HAC-334 established.
+      - name: The boards, captions and manifests are derived, not hand-edited
+        run: |
+          set -euo pipefail
+          pnpm run film:derive
+          if ! git diff --exit-code -- \
+            media/hac-336/masters \
+            media/hac-336/captions \
+            media/hac-336/evidence/input-manifest.json \
+            media/hac-336/evidence/scene-map.json; then
+            echo "::error::a derived film artifact differs from its rebuild"
+            exit 1
+          fi
+
+      - name: Every film gate is proven to fail on its own defect
+        run: pnpm vitest run test/hac-336-film-gates.test.mjs
+
+      - name: Explain the failure
+        if: failure()
+        run: |
+          {
+            echo "## Final media gate failed"
+            echo
+            echo "**Invariant.** The judge-facing cut runs under four minutes, shows the"
+            echo "controlled local experiment (HAC-330) and Google Cloud participation"
+            echo "(HAC-324 filmed run) as two proof classes separated by an explicit reset,"
+            echo "and never lets one borrow the other's evidence. Every filmed frame hashes"
+            echo "to a digest the HAC-324 capture manifest promoted. Every factual line maps"
+            echo "to a claim row in the HAC-335 ledger or the HAC-336 filmed-run rows. The"
+            echo "HAC-343 four-arm figure never appears without its evidence-ablation control"
+            echo "on the same board. The opening thirty seconds are legible with the sound"
+            echo "off, and the cut carries no audio track at all."
+            echo
+            echo "**Why it matters.** The video is the one artifact a judge watches before"
+            echo "reading anything. It is also the easiest place for two runs to look like"
+            echo "one, for a crop to quietly exclude an inconvenient line, or for a bounded"
+            echo "result to lose the bound that makes it honest."
+            echo
+            echo "**Authority.** HAC-336 issue contract; HAC-333 owns story, timing and the"
+            echo "muted contract; HAC-324 owns the filmed capture package; HAC-343's media"
+            echo "guardrail owns the four-arm scene; HAC-335 owns the claim ledger."
+            echo
+            echo "**Evidence required.** \`pnpm run check:film\` passing, the derived"
+            echo "artifacts matching their rebuild, and the negative-proof suite showing each"
+            echo "invariant still fails when violated."
+            echo
+            echo "**Do not weaken.** Do not raise the ceiling, do not drop a proof element to"
+            echo "fit the time, do not remove a non-claim to quiet a phrase check, and do not"
+            echo "substitute a frozen HAC-340 reference artifact for filmed footage. If a"
+            echo "derived artifact is reported stale, re-run \`pnpm run film:build\`; if the"
+            echo "video is stale, re-run \`pnpm run film:render\` locally, which needs ffmpeg."
+          } >> "$GITHUB_STEP_SUMMARY"

media/hac-336/README.md

@@ -0,0 +1,173 @@
+# HAC-336 — final media assembly
+
+The judge-facing cut, as a repository-native contract. This issue owns the
+**edit**: which frozen artifact is on screen, for how long, under which proof
+class, saying what. It owns no facts. Every number in the video was frozen by
+HAC-330, HAC-343 or HAC-324 before this package existed, and every board here
+reads those files rather than restating them.
+
+**Runtime 3:49.5 against a 4:00 ceiling. 1920 × 1080, H.264, no audio track.**
+
+## Files
+
+| Path | Role |
+| --- | --- |
+| `evidence/cut.json` | **Authored.** The edit decision list: beats, holds, sources, proof classes, narration, claim citations. The only file here a human writes. |
+| `evidence/filmed-run-claims.json` | **Authored.** Claim rows for the HAC-324 filmed run, each bound to JSON pointers into the frozen record. |
+| `evidence/input-manifest.json` | Derived. Every artifact the cut consumes, with its content digest, plus every declared revision and whether it could be checked. |
+| `evidence/scene-map.json` | Derived. Timestamp → scene → proof class → source artifact → claim. |
+| `evidence/frame-manifest.json` | Derived. One row per beat: the frame, its digest, and the artifact it came from. |
+| `evidence/render-manifest.json` | Derived. What the encoder actually wrote, read back out of the file. |
+| `masters/*.svg` | The six film boards, in the HAC-334 display-list grammar. |
+| `frames/*.png` | The composed holds. Also the reduced-motion equivalent — see below. |
+| `captions/*.vtt`, `*.srt` | The narration track. |
+| `exports/IL-MOT-020-…mp4` | The cut. |
+| `bin/verify-film.mjs` | The gate. Node builtins only. |
+
+## Build
+
+```sh
+pnpm run film:build     # boards -> frames -> captions -> manifests
+pnpm run film:render    # the encode; needs ffmpeg, and is not run in CI
+pnpm run check:film     # the gate
+```
+
+`film:render` resolves `ffmpeg` to an absolute path rather than through `PATH`;
+set `FFMPEG` to an absolute path if your host keeps it somewhere else. The
+resolved binary is recorded in `evidence/render-manifest.json`, so the encoder
+that produced the submission video is a fact rather than whatever the shell found
+that afternoon.
+
+`film:derive` is the subset CI re-runs and diffs: boards, captions and the two
+manifests are pure functions of the cut and the frozen evidence. Frames are not
+— resvg's text rasterisation is not byte-identical across hosts — so they are
+bound by source digest instead, exactly as HAC-334 established for its PNGs.
+
+## Two proof classes, one reset, nothing crossing
+
+The cut is built around a hard divide at **B09**, HAC-333's SB-06.
+
+**Before it — controlled local.** HAC-330's counterfactual (`140 > 130`,
+`WITHHOLD_SERIALIZE` → `120 <= 130`, perturbed evidence → `ALLOW_PARALLEL` →
+`140 > 130`, checks 24/24) and HAC-343's bounded four-arm evaluation. Paper
+field. Deterministic, local, no cloud runtime.
+
+**After it — Google Cloud participation.** The HAC-324 **authoritative filmed
+run**, correlation `ilk-hac340-cloud-1787536029323`: five frames captured while a
+real `gemini-3.5-flash` agent traversed Google ADK 1.35.1 on Cloud Run through
+the Interlock MCP proxy, producing `ALLOW` + receipt, an `EXECUTED` protected
+mutation at `105 <= 130`, an independently authenticated `OBSERVED` read-back at
+`alpha=45`, and Cloud Logging correlation. Ink field.
+
+The gate refuses class-B material before the reset, class-A material after it, a
+filmed capture presented under any class but B, and the frozen HAC-340 reference
+run's correlation id anywhere in judge-facing copy.
+
+### Why the architecture board is new
+
+`IL-DIAG-011` and `IL-DIAG-012` already explain this topology, and they are
+excellent. They also name `interlock-hac340-proxy-00002-wzf` and correlation
+`…1786730369123`, which belong to the **frozen reference run**. Putting either
+beside filmed footage would place two run identities in one act — the precise
+collapse HAC-324 exists to prevent. `IL-DIAG-020` is bound to the filmed run and
+to nothing else.
+
+## What the cut does to filmed evidence
+
+Exactly one thing: a **crop**. A rectangle of the original pixels, scaled
+uniformly into a stage, with board chrome drawn around it. No recolouring, no
+redaction, no compositing of two captures, no text inside the stage.
+
+A 1920 × 1080 terminal capture with its content in the top third is unreadable at
+video bitrates. Cropping to that content changes what a judge can read, not what
+the evidence says. Every crop rectangle is declared in the cut, recorded on the
+frame, and compared by the gate — so a crop that quietly excluded an
+inconvenient line is visible as a rectangle that moved.
+
+All five promoted scenes appear. The gate fails if one is dropped.
+
+## Audio, captions, and reduced motion
+
+**There is no audio track**, and the gate fails if one appears. HAC-333 froze
+this cut as muted: every claim has to survive with the sound off. The captions
+carry the narration text — the words a voice-over would speak, written so that
+recording one later is a matter of reading them aloud rather than re-authoring
+them. Synthetic speech was not generated: a channel no gate can check and no
+human spoke is not an accessibility feature.
+
+**Reduced motion.** The only motion in 3:49 is a 0.4 s crossfade between two
+still holds. It carries a state change and nothing else — every proposition is
+legible on the frame at either end. `frames/` is therefore a complete static
+equivalent of the cut, not an approximation of one: the frame set and the video
+say the same thing, and the scene map orders them.
+
+Nothing on screen implies a frozen result is being recomputed while the viewer
+watches. There are no counters, no typewriter effects, no particles, and no
+agent-thinking cues.
+
+## The first thirty seconds
+
+`B01`–`B05` establish, with the sound off: two intents each valid alone, one
+shared environment carrying one joint bound, and `140 > 130` at display size
+marked `INVALID JOINT STATE`. The gate requires every beat that starts before
+0:30 either to be a frozen board that carries its own copy or to record what a
+muted reader takes from it, so the thesis can never come to depend on the caption
+track.
+
+## The HAC-343 scene
+
+The media guardrail requires Panel 1 and Panel 2 to be one contiguous visual
+unit, so the `0/2` Interlock figure never stands alone as a broader safety claim.
+`IL-PROOF-021` satisfies that literally: the `ablation` state is the `comparison`
+state with the control panel added, on the same board. The per-target lock
+credibility strip (`2/2` serialized, `4/4` parallelized, `2/2` missed) stays
+visible on both, so A3 never reads as a straw man.
+
+The gate checks all four arms, both ablation rows and the credibility strip are
+present on the ablation board, and that the ablation beat immediately follows the
+comparison beat.
+
+## What the cut does not claim
+
+Carried by `IL-PROOF-014` at B19 and `IL-PROOF-022` at B18, and enforced by the
+gate's phrase list: Interlock is not universally safe and not safer than locking;
+no `0%`/`100%` headline over a heterogeneous corpus; no interval or statistical
+significance; no exactly-once, restart safety, target-side atomicity or
+production readiness; Agent Runtime, Agent Gateway, Memory Bank and
+`CONTENT_AUTHZ` did not participate; `ALLOW` is a decision, not a verification or
+an authorization; Cloud Run IAM establishes transport provenance only; the two
+runs are two runs.
+
+Several of those phrases are ones the cut is *required* to say, in the negative —
+a limitations board that could not print "exactly-once" could not disclaim it
+either. The phrase check therefore flags a hit only when nothing nearby negates
+it, and `test/hac-336-film-gates.test.mjs` separately proves the bare assertive
+form of each still fails.
+
+## Cold read
+
+**Not run. No result is claimed.**
+
+`media/hac-341/cold-read/` is the moderator kit and it is the protocol for this
+cut too: three technically competent readers unfamiliar with the build, tested
+one at a time, no pre-explanation. Until three real readers have completed it,
+this package stays `READY_FOR_HUMAN_TEST` and nothing here may describe the media
+as frozen. LLM judges, agent review and automated browser tests are not
+substitutes.
+
+## Verify
+
+```sh
+pnpm run check:film
+pnpm vitest run test/hac-336-film-gates.test.mjs
+```
+
+The gate fails on: a cut over four minutes; an encoded duration that disagrees
+with the derived one; a frame that changed after the encode; a filmed frame whose
+bytes do not hash to the digest the capture manifest promoted; a promoted scene
+dropped without record; a crop that moved; a claim citation with no ledger row; a
+filmed-run row whose pointer stopped resolving; a forbidden phrasing asserted
+without negation; a missing boundary statement; the ablation control separated
+from its comparison; a beat in the opening thirty seconds with no muted reading;
+a caption that drifted from its narration; an audio track; a declared input whose
+bytes moved; and a declared revision the evidence no longer carries.