feat(cli): add tts command for local text-to-speech via Kokoro-82M (#201)

* feat(cli): add `tts` command for local text-to-speech via Kokoro-82M

Adds `hyperframes tts` — generate speech audio locally using Kokoro-82M
(ONNX), no API key needed. Mirrors the transcribe command architecture.

- New command: `hyperframes tts "text" --voice af_heart --output speech.wav`
- 54 voices across 8 languages, ~5x realtime on CPU
- Auto-downloads model (~311 MB) + voices (~27 MB) to ~/.cache/hyperframes/tts/
- Requires Python 3.8+ with kokoro-onnx installed
- Extracted shared `downloadFile` utility from whisper/manager.ts with
  atomic .tmp→rename to prevent partial download corruption
- Added hyperframes-tts skill with voice selection guide
- Updated CLAUDE.md with TTS docs, voice table, and skill reference

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

* docs(tts): improve skill per skill-creator guidelines

- Move trigger info from body to frontmatter description
- Remove `trigger` field (not a valid frontmatter field)
- Remove CLI flag docs Claude can derive from --help
- Remove redundant voice tables (keep content-to-voice mapping)
- Fix composition audio example to use actual <audio> element pattern
- Keep non-obvious workflows: TTS+transcribe for captions, long scripts

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

* docs(tts): add guidance for using external TTS sources

Help users understand when to use cloud TTS (voice cloning, broader
languages, higher quality) vs the built-in Kokoro model, and how
external audio integrates into the same composition workflow.

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

* docs(tts): prioritize HeyGen API as recommended cloud TTS

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

* docs(tts): remove external TTS section for now

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

* fix(tts): set required: false on input arg so --list works standalone

Citty treats positional args as required by default unless explicitly
set to required: false. Without this, `hyperframes tts --list` fails
with "Missing required positional argument".

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

* feat(tts): add --help examples and fix required:false for --list

Add examples section to `tts --help` matching the pattern from other
commands (transcribe, render, etc.). Fix citty positional arg requiring
explicit `required: false` for --list to work standalone.

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

* docs: add CLI command checklist to CLAUDE.md

Ensure new commands always get --help examples in help.ts.

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/help.ts

@@ -124,6 +124,14 @@ const COMMAND_EXAMPLES: Record<string, Example[]> = {
     ["Install to Cursor (project-level)", "hyperframes skills --cursor"],
     ["Install to specific tools", "hyperframes skills --claude --gemini"],
   ],
+  tts: [
+    ["Generate speech from text", 'hyperframes tts "Welcome to HyperFrames"'],
+    ["Choose a voice", 'hyperframes tts "Hello world" --voice am_adam'],
+    ["Save to a specific file", 'hyperframes tts "Intro" --voice bf_emma --output narration.wav'],
+    ["Adjust speech speed", 'hyperframes tts "Slow and clear" --speed 0.8'],
+    ["Read text from a file", "hyperframes tts script.txt"],
+    ["List available voices", "hyperframes tts --list"],
+  ],
   transcribe: [
     ["Transcribe an audio file", "hyperframes transcribe audio.mp3"],
     ["Transcribe a video file", "hyperframes transcribe video.mp4"],