feat(cli,core): standalone transcribe command, transcript normalization, caption lint rules (#151)

* feat(cli,core): add standalone transcribe command, transcript normalization, and caption lint rules

- Add `hyperframes transcribe` command for transcribing audio/video and importing
  existing transcripts (SRT, VTT, OpenAI Whisper API JSON, whisper.cpp JSON)
- Add transcript format normalizer (normalize.ts) with auto-detection and
  conversion to standard [{text, start, end}] word arrays
- Upgrade default whisper model from base.en to small.en for better accuracy
- Add --model and --language flags to both `transcribe` and `init` commands
- Extract shared patchCaptionHtml() to eliminate duplication between init.ts
  and transcribe.ts (init.ts reduced by ~55 lines)
- Add 3 caption lint rules: caption_exit_missing_hard_kill,
  caption_text_overflow_risk, caption_container_relative_position
- Update captions skill with model guide, format docs, music guidance,
  text overflow prevention, caption exit guarantee pattern
- Expand captions skill trigger to cover lyrics, karaoke, lyric videos

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs(cli): add transcribe command and --model/--language flags to CLI docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(cli): fix blank template lint issues

- blank/index.html: remove data-start from video (was nested in timed parent),
  add class="clip" for initial hidden state
- blank/captions.html: add max-width + overflow:hidden to prevent text clipping,
  add tl.set hard kill after exit tween to prevent stuck captions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: add lint-after-edit rule to repo and project CLAUDE.md

Agents must run `npx hyperframes lint` after editing compositions.
Also expand captions skill description in project template.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* style: format _shared/CLAUDE.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/cli/src/whisper/manager.ts

@@ -6,7 +6,7 @@ import { get as httpsGet } from "node:https";
 import { pipeline } from "node:stream/promises";
 
 const MODELS_DIR = join(homedir(), ".cache", "hyperframes", "whisper", "models");
-const DEFAULT_MODEL = "base.en";
+const DEFAULT_MODEL = "small.en";
 
 export type WhisperSource = "env" | "system" | "brew" | "build";