fix(skills): align media guidance with CLI contracts

[miguel-heygen]

What

• Correct TTS guidance to use the local Kokoro CLI only with supported flags and route HeyGen timestamp generation through the bundled provider script.
• Replace unsupported multilingual Whisper model examples with the CLI-supported large-v3 model.
• Add video as an ingest-only media type so documented resolve --from … --type video works.
• Regenerate the skill manifest.

Why

The shipped media skills advertised tts --provider, tts --words, multilingual --model small, and video ingest commands that CLI 0.7.52 rejected. These mismatches forced manual workarounds during an otherwise clean Windows render.

How

The docs now mirror the published CLI help and provider-specific scripts. The media registry declares an ingest-only video type without adding a generative video provider, and an end-to-end test verifies that a local MP4 is frozen and registered.

Test plan

• node --test skills/media-use/scripts/resolve.test.mjs skills/media-use/scripts/lib/registry.test.mjs
• npx oxlint skills/media-use/scripts/lib/registry.mjs skills/media-use/scripts/lib/registry.test.mjs skills/media-use/scripts/resolve.test.mjs
• pre-commit skill-manifest and formatting hooks