docs: log beat-specific grading milestone

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bg76sLc43Wc3j5ZcLkboYR

docs/cinematic-highlight-poc-plan.md

@@ -71,11 +71,12 @@ numpy<2, transformers must be 4.x, audiocraft/xformers unusable here, `HF_HUB_DI
 
 ### Phase 3 — Iterate to quality
 Ranked from the first render's evidence:
-- [~] P3.1 Stronger filmic grade in `HighlightFfmpegRenderer.cinematicVisualFilter`: S-curve (curves
-      medium_contrast) + teal-orange colorbalance + eq + unsharp + vignette (replaces the weak fixed eq).
-      Verified visually (richer blue, warm highlights, contrast, vignette). NOTE: still ONE uniform look —
-      not yet beat/category-specific (that needs a validated grade enum plumbed via EditDecision). Only the
-      highlight renderer changed; multi-clip FfmpegEditRenderer untouched.
+- [x] P3.1 Filmic grade in `HighlightFfmpegRenderer.cinematicVisualFilter`: S-curve + teal-orange
+      colorbalance + eq + unsharp + vignette (replaces the weak fixed eq). Only the highlight renderer
+      changed; multi-clip FfmpegEditRenderer untouched.
+- [x] P3.1b **Beat-specific grading** (a0b6023): grade now varies by story beat (read from the EditPlan
+      style key, no EditDecision/serialization change) — opening=cool/soft (linear_contrast), rising=balanced
+      (medium_contrast), hero=rich/warm (strong_contrast). Verified visually (calm→dramatic arc) + unit test.
 - [x] P3.2 True-peak safety: added `alimiter=level=disabled:limit=0.72` after loudnorm in the audio mix.
       VERIFIED by re-render: project true peak 0.0 dBFS (clipping) → **-1.7 dBFS**; per-highlight -1.7/-2.7/
       -2.8 (all <= -1.5 dBTP gate); integrated loudness -16.3 LUFS. (First pass at limit=0.79 gave -1.3 on
@@ -100,7 +101,10 @@ Ranked from the first render's evidence:
   0fcfca9 (render quality).
 - 2026-07-22: **Phase 3.3 done & verified.** Premium overlay styling (soft shadow, alpha fade). Committed
   24bd1d7. Combined re-render (grade+limiter+overlays) verified: TP -2.5/-2.6/-2.8 dBFS, I -16.3 LUFS,
-  1080p/27.3s; mvn verify 246/0/0/0. Next: P3.4 real CV selection / beat-specific grade (needs grade enum).
+  1080p/27.3s; mvn verify 246/0/0/0.
+- 2026-07-22: **Beat-specific grading done & verified** (a0b6023). Grade varies per story beat; final
+  re-render TP -2.3/-2.5/-2.8 dBFS, I -16.3 LUFS, 1080p/27.3s; mvn verify 247/0/0/0. Phase 3 visual/audio
+  craft items complete. Next: P3.4 real CV selection, P3.5 music/SFX fit, P3.6 frozen thresholds + review.
 
 ## Deferred (until output-quality gate passes)
 Production hardening: Spring Security/OIDC, PostgreSQL/Testcontainers, containers/K8s, CI/CD, distributed