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/INDEX.md

@@ -58,6 +58,7 @@ Key capability families to look for in the output:
 | `audio_processing` | — | FFmpeg-based local tools |
 | `enhancement` | — | Mixed providers |
 | `analysis` | — | Mixed providers |
+| `character_animation` | — | Local character specs, SVG rigs, pose libraries, action timelines, previews, and QA |
 | `graphics` | — | Local rendering tools |
 | `music_generation` | — | Single-provider |
 | `subtitle` | — | Pure Python |
@@ -92,7 +93,7 @@ Key capability families to look for in the output:
 | Enhancement Strategy | `creative/enhancement-strategy.md` | Overlay placement and density | `ffmpeg` |
 | Data Visualization | `creative/data-visualization.md` | Chart type selection, animation, label placement | `d3-viz`, `remotion-best-practices` |
 | Video Stitching | `creative/video-stitching.md` | Multi-clip assembly, AI clip chaining, spatial composition | `ffmpeg`, `video_toolkit` |
-| Video Gen Prompting | `creative/video-gen-prompting.md` | Universal video generation prompt vocabulary | `ai-video-gen`, `ltx2`, `create-video` |
+| Video Gen Prompting | `creative/video-gen-prompting.md` | Universal video generation prompt vocabulary; **canonical 5-aspect spec** (Subject / Motion / Scene / Spatial / Camera); ~200 cinematography primitives | `ai-video-gen`, `ltx2`, `create-video` |
 | ↳ Seedance Prompting | `creative/prompting/seedance-prompting.md` | **Preferred premium default.** Seedance 2.0 8-component structure, multi-shot, lip-sync, reference-to-video | `seedance-2-0`, `ai-video-gen` |
 | ↳ Grok Prompting | `creative/prompting/grok-prompting.md` | Grok image/video prompting, edit flows, reference-image video | `grok-media` |
 | ↳ Sora Prompting | `creative/prompting/sora-prompting.md` | Sora 2 structured template, advanced fields | `ai-video-gen` |
@@ -127,6 +128,7 @@ Pipeline type skills provide production guidance for specific video formats, ind
 | Long-Form | `creative/long-form.md` | YouTube 10+ min â€" chapters, retention, end screens |
 | Screen Recording | `creative/screen-recording.md` | Code walkthroughs, tutorials, software demos |
 | Animation Pipeline | `creative/animation-pipeline.md` | Motion graphics, easing, transitions, composition |
+| Character Animation Pipeline | `pipelines/character-animation/` | Rigged local cartoon characters, pose libraries, action timelines, SVG/Canvas/Remotion/HyperFrames rendering |
 | Cinematic | `creative/cinematic.md` | Letterbox, film pacing, layered audio, color grading |
 
 ## Pipeline Stage Director Skills