P13.1: final vibe integration — playthrough validation, full golden sweep, finalized docs

Integration-only (no logic changes). Validated the full candy vibe in the booted
iPhone sim and brought every artifact in line with the shipped candy palette +
Triple Treat SFX bank.

Goldens — swept all 23:
- Refreshed 15 that predated the candy palette (P12): p6_idle_t0, p6_idle_mid,
  p6_select, p7_restart, p5_swap_before/after, p6_anim_swap/clear/fall/after,
  p6_fx, p6_fx_after, p6_fx_match, p6_inputlock_board, p11_combo_deep — re-captured
  via the documented M3TE_* hooks.
- Left 5 unchanged (board+HUD region byte-identical to the current build, verified
  by cropped-region hash): p4_board, p4_hud, p9_polish, p7_win, p7_lose.
- Removed 3 obsolete pre-board orange-quad goldens (app no longer renders them):
  p0_quad, p0_input_before, p0_input_after.

Docs — README.md:
- Section 2 now describes the candy board (not the old orange quad) and points at
  goldens/p6_idle_t0.png; dropped the removed p0_* references.
- Added the final audio model: Triple Treat SFX provenance + per-cue mapping, the
  per-round ascending cascade (one combo cue per round, clamped at combo5), the
  WAVE/mono/44100/Int16 @ -15 dBFS format spec, and the cue-log capture commands.
- Added image-art asset regeneration (codex imagegen via codex exec + sips
  normalize to exact per-asset dims/format).

Gate: ios-sim build links (exit 0); 21/21 pure-sx logic tests pass. Playthrough
evidence (cue NSLog ascending combo1..combo5 + win/lose stingers, screenshots)
captured in the worker report.

README.md

@@ -32,7 +32,9 @@ bash tools/run_tests.sh
 ### 2. iOS Simulator build + launch
 
 Build the app for the simulator, then install/launch it on an available device
-and screenshot the rendered scene (blue background + a centered orange quad).
+and screenshot the rendered scene — the brighter **candy** match-3 board: a soft
+pink→lavender→blue gradient background, an 8×8 grid of glossy candy gems on cream
+cell tiles, and a grape candy HUD card (score / moves) above the grid.
 
 ```bash
 # Build the .app bundle (sx-out/ios/M3te.app):
@@ -53,10 +55,16 @@ xcrun simctl launch booted co.swipelab.m3te
 xcrun simctl io booted screenshot /tmp/m3te.png
 ```
 
-The screenshot should match `goldens/p0_quad.png` (a centered orange quad over a
+The screenshot should match `goldens/p6_idle_t0.png` (the resting candy board),
-blue clear), modulo the status-bar clock — pixel-exact equality is not required.
+modulo the status-bar clock — pixel-exact equality is not required; compare the
-A tap on the quad flips its color (orange ↔ green); see
+board + HUD region, not the top status strip. A tap selects a cell; a swipe
-`goldens/p0_input_before.png` / `goldens/p0_input_after.png`.
+between two adjacent gems commits a swap (legal swaps cascade + score, illegal
+ones ping back). The deterministic capture hooks below pin a chosen scene so each
+golden reproduces from a clean checkout.
+
+> The earlier `p0_*` goldens (a pre-board orange quad over a blue clear, from the
+> P0 foundation slice) were removed in P13.1: the app no longer renders that
+> scene, so they could only ever mislead.
 
 ### Deterministic animation capture (P6.3)
 
@@ -197,3 +205,118 @@ env SIMCTL_CHILD_M3TE_ANIM_TIME=0 SIMCTL_CHILD_M3TE_SELECT=27 \
 
 The selection gloss is purely visual: it never gates input (`BoardAnim.active`
 owns gating) and never touches board / score / move state.
+
+## Audio bank (P10) — final model
+
+The SFX bank (`audio.sx`) is a purely additive layer over iOS **System Sound
+Services** (AudioToolbox, reached by `#foreign` FFI exactly as the platform reaches
+UIKit/Metal). Each cue is loaded once at startup into its own `SystemSoundID`;
+playback is a single C call. The bank only plays when *every* cue loaded (`loaded`
+gate), so a partial/failed bank mutes rather than playing a stale id. It never
+reads or mutates score / board / move state — `board_view` and the frame loop just
+tell it an event happened.
+
+### Provenance — the user-provided "Triple Treat SFX" pack
+
+The nine shipped cues are best-fit selections from the user-supplied **Triple Treat
+SFX** pack (`Triple_Treat_SFX.zip`, ~30 MB, 280 Unity-style files). The pack itself
+is **not committed** — only the selected, converted cues live in `assets/audio/`;
+the source archive is kept outside the repo (in `~/Downloads`). Full per-cue notes
+are in `assets/audio/LICENSE.txt`. The shipped game never re-synthesizes anything;
+it only loads the finished WAVs.
+
+| cue          | game event                         | pack source (under `Triple Treat SFX/`) |
+|--------------|------------------------------------|------------------------------------------|
+| `swap.wav`   | every committed swipe (subtle)     | `Transition SFX/Swipe FX 1-RCM.wav`      |
+| `match.wav`  | first clear of a legal move (pop)  | `Pop:Bubble SFX/Pop FX 5-RCM.wav`        |
+| `combo1.wav` | cascade round 1 (dullest)          | `Match SFX/Match FX 2-RCM.wav` (~1.7 kHz)|
+| `combo2.wav` | cascade round 2                    | `Match SFX/Match FX 4-RCM.wav` (~2.1 kHz)|
+| `combo3.wav` | cascade round 3                    | `Match SFX/Match FX 6-RCM.wav` (~3.2 kHz)|
+| `combo4.wav` | cascade round 4                    | `Match SFX/Match FX 7-RCM.wav` (~4.7 kHz)|
+| `combo5.wav` | cascade round ≥5 (brightest)       | `Match SFX/Match FX 3-RCM.wav` (~6.8 kHz)|
+| `win.wav`    | level won (stinger)                | `Success:Power-Up SFX/Power Up FX 1-RCM.wav` |
+| `lose.wav`   | level lost (stinger)               | `Fail SFX/Fail FX 2-RCM.wav`             |
+
+The Match-FX set does not cleanly pitch-ascend, so `combo1..5` are ordered by
+ascending **spectral brightness** (centroid 1.68 < 2.09 < 3.18 < 4.70 < 6.77 kHz)
+so a deeper cascade reads as more exciting.
+
+### Per-round ascending cascade
+
+The cascade plays **one ascending cue per cascade round** — round 1 → `combo1`,
+round 2 → `combo2`, … clamped at `combo5` — *not* a single end-of-move sound. Each
+cue fires on the move's animation timeline, edge-triggered as that round's clear
+begins: the frame loop (`main.sx`) diffs `cascade_rounds_started(elapsed, rounds)`
+against `BoardAnim.cascade_fired` and plays the next combo cue per newly-cleared
+round (`sfx_cascade`). The depth→index clamp (`cascade_cue_index`: depth ≤ 1 → 0,
+depth ≥ 5 → 4) is pure + headless, snapshot-tested by `tests/cascade_cue.sx` and
+`tests/cascade_rounds.sx`. A single match (one round) plays only the `match` pop —
+no combo cue. The `swap` cue plays for any committed gesture (legal or the reverted
+ping-back); a legal move adds the `match` pop on its first clearing round; the
+`win`/`lose` stinger fires once, edge-triggered, as the banner comes up.
+
+### Format / level spec
+
+Every cue is delivered in exactly the form System Sound Services loads directly:
+**WAVE / mono / 44100 Hz / signed-16-bit PCM**. The pack sources are 24-bit /
+48 kHz / stereo; each was down-mixed to mono, trimmed to its punchy window, eased
+in with a short fade, rounded out with a cosine fade-out tail, and **peak-normalized
+to a gentle −15 dBFS** (the user rejected aggressive SFX twice). The candy character
+of the pack is preserved — the cues are not re-synthesized.
+
+### Capturing the cue ordering
+
+Every play is `NSLog`'d, so a playthrough's cue order is readable from the device
+log. The deep cascade (`M3TE_FX=11`, depth-5 on seed 1337) must be launched **live**
+(no `M3TE_ANIM_TIME` pin) so the timeline advances and the per-round cues fire in
+sequence:
+
+```bash
+# Deep cascade, live — fires combo1..combo5 one per round on the timeline:
+xcrun simctl terminate booted co.swipelab.m3te
+SIMCTL_CHILD_M3TE_FX=11 xcrun simctl launch booted co.swipelab.m3te
+xcrun simctl spawn booted log show --last 20s \
+    --predicate 'eventMessage CONTAINS "[sx] audio"' --style compact
+# Win / lose stingers (also live so the banner edge-triggers the cue):
+SIMCTL_CHILD_M3TE_TARGET=0     xcrun simctl launch booted co.swipelab.m3te   # cue win
+SIMCTL_CHILD_M3TE_MOVE_LIMIT=0 xcrun simctl launch booted co.swipelab.m3te   # cue lose
+```
+
+## Asset regeneration
+
+The shipped game only loads finished assets; the steps below rebuild them and are
+never run at play time. Refresh any affected `goldens/` after an art change.
+
+### Audio (the SFX bank)
+
+The shipped cues are the Triple Treat selections above, converted to the canonical
+container with `afconvert` (WAVE / `LEI16` / 44100 / mono) and verified with
+`tools/measure_pitch.py` — the combo cues' spectral centroids must ascend
+monotonically (and beat `clear.wav`'s ~784 Hz CC0 baseline reference clip).
+`tools/synth_audio.py` is the build-time DSP path (down-mix, trim, fade, peak-
+normalize, optional resample). The 30 MB pack and its `.meta` / `__MACOSX` cruft
+are not committed.
+
+### Image art
+
+Real art is produced with codex's built-in **`imagegen`** tool through `codex exec`,
+then `sips`-normalized to each asset's exact dimensions and source format:
+
+| asset                       | dims (px) | format | role                              |
+|-----------------------------|-----------|--------|-----------------------------------|
+| `assets/board/background.png` | 863×1822  | PNG    | full-view candy gradient backdrop |
+| `assets/board/cell.png`       | 128×128   | PNG    | one grid cell tile                |
+| `assets/gems/gems.png`        | 768×128   | PNG    | 6 gem columns (a gem's UV column = its index) |
+| `assets/fx/particle.png`      | 256×256   | PNG    | soft match-burst sprite (tinted per gem) |
+
+```bash
+# 1. Generate (codex's imagegen tool, driven non-interactively):
+codex exec "use the imagegen tool to render <prompt for the asset>"
+# 2. Normalize to the exact per-asset dims + format, e.g. the gem sheet:
+sips -z 128 768 --setProperty format png <generated>.png --out assets/gems/gems.png
+```
+
+After any art change, re-capture the affected goldens with the deterministic hooks
+above (`M3TE_ANIM_TIME` / `M3TE_SELECT` / `M3TE_FX` / `M3TE_TARGET` /
+`M3TE_MOVE_LIMIT` / `M3TE_RESTART`) and state per golden whether it was refreshed,
+left unchanged, or removed.