docs(prompting): adopt 5-aspect video specification across skills

Incorporate the structured taxonomy from Lin et al. "Building a Precise
Video Language with Human-AI Oversight" (CMU/Harvard, arXiv 2604.21718v2).
The paper proves prompts structured around five aspects (Subject /
Subject Motion / Scene / Spatial Framing / Camera) unlock controllable
cinematography in fine-tuned video generation models. Off-the-shelf VLMs
already nail subject and scene; the gains live in motion, spatial, and
camera, which prompts routinely omit.

Universal layer (skills/creative/video-gen-prompting.md, +125 lines):
- 5-aspect prompt skeleton replaces flat formula
- Camera movements regrouped (translation / rotation / lens-only) with
  dolly!=zoom, pan!=truck, bird's-eye!=aerial disambiguations
- New primitive tables: camera height, camera angle, POV, lens
  distortion (fisheye vs barrel), focus / DoF (rack / pull / tracking),
  playback speed (6 modes), subject transitions
- Order-matters and self-contained-prompt rules
- Identity anchoring rule for multi-shot
- Strict static-shot rule, anti-subjective callout, overlays-not-depth
- Per-model word-count guidance

Per-model guides (sora, veo, hunyuan, ltx, seedance):
- Add the primitives each model honors literally
- Word-count sweet spots per model
- Strengthen seedance verbatim-identity and subject-transition guidance

Pipeline directors (cinematic / explainer / animation scene-director,
cinematic / explainer asset-director):
- 5-aspect scene-plan checklist (per-pipeline adapted)
- Overlays-not-depth callout
- Pre / critique / post self-review loop for generation prompts

Reviewer (skills/meta/reviewer.md):
- CHAI critique-quality rules: accurate / complete / constructive
- Critical findings now require a proposed_fix

Storytelling, cinematic, broll, video-reference-analyst:
- Anti-subjective rule (replace mood adjectives with visual causes)
- Camera-intent-per-beat for script writers
- POV column in stock-footage query templates
- 5-aspect structured output mandatory for reference-video analysis

skills/INDEX.md: video-gen-prompting marked as canonical 5-aspect spec.

skills/pipelines/animation/scene-director.md

@@ -85,9 +85,25 @@ Recommended metadata keys:
 - `tool_path_map`
 - `reusable_motifs`
 
-### 5. Quality Gate
+### 5. 5-Aspect Scene-Plan Checklist
+
+> Every scene must specify all five aspects, BUT the load shifts with the scene's `animation_mode`. Manim and other diagrammatic/programmatic scenes care most about **Subject** and **Spatial Framing** — Camera and Subject Motion in the cinematographic sense often map to N/A or to abstract equivalents. AI-video / `image_animation` / `anime_scene` scenes care about all five and behave like cinematic shots. Marking an aspect as N/A is allowed but must be explicit per scene; silent omission is forbidden.
+>
+> 1. **Subject** — type + key visual attributes; for Manim, the equation/object/graph being foregrounded; for `anime_scene`, the character or environment in focus.
+> 2. **Subject Motion** — for Manim, the order of `Create`/`Transform`/`FadeIn` and what each animation conveys; for AI-video, the actions and interactions in temporal order.
+> 3. **Scene** — overlays (separately!) + POV + setting + time of day + scene dynamics. For Manim, "setting" is the canvas background + axis style; for `anime_scene`, the environment + lighting gradient.
+> 4. **Spatial Framing** — shot size + position-in-frame + depth (FG/MG/BG) + camera-height-relative; and how those CHANGE. Manim cares about layout grid + element positions; AI-video cares about full cinematographic framing.
+> 5. **Camera** — playback speed → lens distortion → height → angle → focus/DoF → steadiness → movement. For Manim and pure motion-graphics, default to N/A unless using a virtual camera move (`MoveCamera`, `self.frame`). For `anime_scene` and AI-video, specify fully.
+>
+> Tie this back to `animation_mode` in scene metadata: a Manim scene that lists Camera fully is over-specified; an AI-video scene that omits Camera is under-specified. See `skills/creative/video-gen-prompting.md` for the primitive vocabulary.
+
+> **Overlays callout.** Overlays (titles, subtitles, HUD, watermarks, framing graphics, lower-thirds, `hero_title`, `section_title`, `provider_chip`) are NOT part of the scene's foreground/midground/background depth axis. List them separately in scene metadata (`overlays: [...]`) with content and placement. Never describe an overlay as "in the foreground" — that confuses both downstream tools and any video-understanding model that re-analyzes the output.
+
+### 6. Quality Gate
 
 - every scene has a clear timing intent,
+- the 5-aspect checklist is satisfied for the scene's `animation_mode` (with explicit N/A where appropriate),
+- overlays live under `overlays:`, never inside the framing description,
 - the transition system is limited and meaningful,
 - the tool path is explicit,
 - the sequence feels like one designed system.