docs(render): S3 chunk 1 contract — transcript kinds, fixtures, print-only emitter

Runs after chunk 3 (LC/SC need per-cell terrain). One print-only flag,
the FW0 parser extended for the OH kinds, the five captures as fixtures
in the existing still-frame conformance harness, and an offline signature
diff as the transcript gate. No validator, no canonical format.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/research/2026-09-01-overhaul/s3-walk-ownership-map.md

@@ -592,3 +592,82 @@ DELETE (no retail counterpart):
   their read sites removed together (the test enforces both directions);
 - the register: no row is added (every deletion removes an acdream-only
   rule); any KEEP item still lacking a CPU/GPU equivalence pin gets one.
+
+## 11. Chunk 1 contract — transcript kinds, fixtures, and the print-only emitter (lead, 2026-09-03; runs AFTER chunk 3, because `LC`/`SC` only exist once terrain is per cell)
+
+### 11.1 What exists (verified in the tree at `542b049b`)
+
+- The FW0 test-side parser `tests/AcDream.App.Tests/Rendering/Walk/WalkOracleTrace.cs`
+  parses `F`, `P`, `LS`, `BLD`, `DI`, `DC` and drops the truncated detach
+  frame; `WalkTraceReplay.cs` rebuilds the camera from the `P` pose (retail
+  projection globals, +Y forward) and drives `RetailFrameWalk` over
+  DAT-adapter world data; `WalkTraceConformanceTests` (InstalledDat lane)
+  already proves the FW0 still fixtures' first frames position-for-position
+  and `WalkOracleTraceTests` pins per-fixture facts. `Load(name)` is rooted
+  at `docs/research/2026-08-30-fw-walk-oracle/`.
+- The five OH captures are committed under
+  `docs/research/2026-09-01-overhaul/oh-capture/` (README there): per pose a
+  walk log (adds `LC`/`SC`/`EC`/`OC` to the FW0 kinds), a parts log (`PD`,
+  `DM`), and an alpha-depth log (`AM`, `FL`, `PM`, `PC`); line formats are in
+  `tools/walk-oracle/oh/*.cdb.template`. Same `F`/`P` framing; same detach
+  rule.
+
+### 11.2 Production behavior change (the one allowed piece of evidence infrastructure)
+
+- **B1 — one print-only flag, `ACDREAM_DUMP_WALK_TRANSCRIPT=1`**, read once
+  into `RuntimeOptions` (rule 4) and owned by `RenderingDiagnostics` (rule
+  5), with its `docs/launch-options.md` row in the same commit
+  (`LaunchOptionsDocumentationTests` enforces both directions). When set,
+  the production walk prints, to the existing diagnostics sink, exactly the
+  OH line kinds at the points retail's breakpoints sit: `F n` + `P …` at
+  the frame root (`SmartBox::RenderNormalMode` @0x00453aa0 — the camera
+  cell, origin and quaternion in retail's storage order), `LS` at the
+  landscape turn, `LC <cell>` / `SC <cell>` per land cell (chunk 3's events,
+  with the LOD id `x*8+y+1`), `BLD <cell>` at the building turn, `DI <cell>`
+  at DrawInside, `DC pv=<0|1> ov=<n> n=<k>: <cells…>` at every DrawCells
+  (pv 0 = interior pview, 1 = outdoor pview — a stable stand-in for
+  retail's pointer, which the parser already ignores), `EC <cell>` per shell
+  draw, `OC <cell>` per object-list turn. NOTHING else changes: no admission,
+  depth state, or draw order may depend on the flag (the print sits AFTER
+  each decision, never inside it).
+- **B2 — parser extension.** `WalkOracleTrace` learns `LC`, `SC`, `EC`, `OC`
+  as event kinds and gains `Load(root, name)` (or a fixture-set enum) so the
+  OH captures load from their own directory; the parts and alpha-depth
+  kinds get their own small readers (`PD`/`DM` → gfx id, force, bound, cell;
+  `AM`/`FL`/`PM`/`PC` per the template's documented fields) — read-only
+  records, no validator, no canonical JSONL, no new tool
+  ([[feedback-evidence-infrastructure-sink]]).
+- **B3 — fixtures + pins.** The five walk captures join
+  `WalkOracleTraceTests.AllFixtures` (parse + complete-frame pin) and the
+  four kit poses join `WalkTraceConformanceTests`' still-fixture theory at
+  the DI/DC/BLD/LS level (first complete frame, position-for-position, the
+  SAME harness as FW0 — the cathedral-arrival capture's root is `f4180108`,
+  not FW0's `f4180106`, so it is a NEW pose row, not a replacement). The
+  `LC`/`SC` sequences of both cathedral poses become the chunk-3 order pin's
+  fixture (§9 T1) if chunk 3 landed with a hand-extracted one. The parts
+  and alpha-depth logs are imported and parsed (B2) but pinned only where a
+  later chunk/S4 names a consumer — no speculative assertions.
+- **B4 — the automated transcript gate (§6).** A Release run with the flag at
+  the four kit poses (session-config login + `/teleloc` from the self-gate
+  kit) produces acdream transcripts; the test-side comparison is the
+  existing signature diff (`WalkTraceReplayContext.Signature`) extended to
+  the new kinds, run offline over the two files — a FACT-level report per
+  pose (first divergent event and position), consumed by the S3 review and
+  G3. It is a test-side script, not a client subsystem.
+
+### 11.3 Tests
+
+- T1: the flag off → zero output and zero allocation on the walk path
+  (the existing `WalkFrameDriver` allocation pins stay green).
+- T2: the flag on, one synthetic interior frame → the printed lines parse
+  with the extended `WalkOracleTrace` into the same events the driver
+  recorded (emitter/parser round trip).
+- T3: `AllFixtures` + the still-fixture theory rows for the four OH kit
+  poses (InstalledDat lane); the two cathedral `LC`/`SC` order pins.
+- T4: `LaunchOptionsDocumentationTests` green with the one new row.
+
+### 11.4 Out of scope
+
+Any validator, canonical format, or dashboard; any behavior change; any
+second flag. If the gate report shows a divergence, that is a finding for
+the S3 review round, fixed in the owning chunk's follow-up — not in chunk 1.