RX-7 rotary loops: extracted from the owner's real car footage

- Sourced from c-finished-videos/2026-07-10 sessions (the actual FD)
- Scanned 6 min of audio per-second for RMS/dominant-freq/spectral
  flatness; picked the most tonally-stable stretches (idle: 272-288s
  @ ~99Hz flatness<0.02; rev: 319.5-327s @ ~105Hz, louder)
- Zero-crossing trim + 150ms equal-power tail-to-head crossfade =
  seamless loops (seam jump 0.001 / 0.005); normalized to -3dBFS
- Shipped as assets/audio/rx7_idle_loop.ogg + rx7_rev_loop.ogg (236KB);
  wav masters mirrored to NAS 001-1993 Mazda RX-7/sound/
- ROTARY_SOUND.md updated: only Studio upload + 2 asset IDs remain

docs/ROTARY_SOUND.md

@@ -1,4 +1,27 @@
-# Real 13B rotary engine sound (rx7_fc)
+## Status: loops are BUILT ✅ — awaiting Studio upload
+
+Real 13B loops were extracted from the owner's own drive footage
+(`/mnt/user/data/c-finished-videos/2026-07-10/`, same car) and processed on the
+workstation. They live at:
+
+- `assets/audio/rx7_idle_loop.ogg` — 15.9 s steady idle (~99 Hz fundamental,
+  scanned as the most tonally stable stretch of the session; seam jump 0.001)
+- `assets/audio/rx7_rev_loop.ogg` — 7.4 s held higher-RPM pull (~105 Hz,
+  louder section; seam jump 0.005)
+- Masters (`.wav` + `.ogg`) mirrored to the NAS:
+  `.../001-1993 Mazda RX-7/sound/`
+
+**Remaining (owner, in Studio): upload the two `.ogg` files** (Asset Manager →
+Import, or Creator Dashboard → Audio), wait for moderation, then paste the two
+asset IDs into `CAR_SOUNDS.rx7_fc` in `src/client/SoundController.luau`.
+
+If a longer/angrier rev is wanted later, more source material exists in the
+other sessions under `c-finished-videos/` — the extraction is repeatable
+(method below).
+
+---
+
+# Pipeline reference (how the loops were made / how to redo them)
 
 The RX-7 must sound like a rotary. The pipeline: the owner's own recordings →
 processed into two seamless loops on this workstation → uploaded in Studio →