docs(cli): add tts command to --help groups, CLI docs, and CLAUDE.md checklist (#240)

The tts command was implemented (PR #201) but never added to the root-level
help display or documentation. This adds it to:

- help.ts GROUPS (AI & Integrations) so it appears in `hyperframes --help`
- docs/packages/cli.mdx with usage examples and flag reference
- CLAUDE.md "Adding CLI Commands" checklist: new steps 4-5 require adding
  commands to help.ts groups and docs, preventing future omissions

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

packages/cli/src/help.ts

@@ -53,6 +53,7 @@ const GROUPS: Group[] = [
         "transcribe",
         "Transcribe audio/video to word-level timestamps, or import an existing transcript",
       ],
+      ["tts", "Generate speech audio from text using a local AI model (Kokoro-82M)"],
     ],
   },
   {