reactor-sdk: update for js-sdk 3.0.0 and reactor-sdk 1.1.1

[ggoldens]

Warning

Do not merge before @reactor-team/js-sdk@3.0.0 is published to npm. The JS/React references in this PR document 3.0.0 as the current state, with no hedging — npm install @reactor-team/js-sdk still resolves 2.x today, so this content is only accurate once the real release goes out. reactor-sdk (Python) is already at 1.1.1 on PyPI, so those changes are accurate right now and could ship independently if that's easier.

Summary

Both references/javascript.md/react.md and references/python.md (plus SKILL.md's gotchas/checklist and references/models.md's roster) described SDK generations that no longer match reality — verified directly against reactor-client-sdks' sdks/js and sdks/python source, not from memory.

JS (@reactor-team/js-sdk 3.0.0, wasm-bindgen over reactor-core):

• sendCommand() now awaits and resolves the real reply (Promise<ReactorMessage | undefined>) instead of firing-and-forgetting.
• ReactorError is a typed class hierarchy now (UnauthorizedError, RateLimitedError, ConflictError, ...) — the old flat {code, message, component, ...} shape and component field are gone.
• New recording/clip API: requestClip/requestRecording/downloadClipAsFile, plus React's ClipPlayer/ClipDownloadButton/useClipDownload — no prior-generation equivalent existed.
• ReactorProvider gained modelTracks; useReactor gained pauseTrack/resumeTrack/requestClip/requestRecording/downloadClipAsFile action bindings.

Python (reactor-sdk, now 1.1.1 on PyPI):

• Full rewrite — a ctypes wrapper over a native library, zero runtime deps.
• send_command awaits its reply too, same as JS.
• ReactorError is a class hierarchy mirroring the JS one (16 shared subclasses), component field gone.
• Reconnection changed shape entirely: disconnect() takes no arguments and is never recoverable; reconnect() resumes the same session directly, no prior disconnect needed. The old disconnect(recoverable=True) + reconnect() dance doesn't exist here — don't port the JS pattern.
• Frame handling and pause/resume moved off Reactor onto Track (track.on_frame, track.pause()/.resume()); Reactor.on_frame was removed in 0.9.0.
• MessageScope, get_capabilities(), get_last_error(), get_remote_tracks(), get_session_info(), and a model_tracks constructor param do not exist in this SDK — several of these were probably assumed present by anyone extrapolating from the JS SDK.

models.md: roster (HappyOyster, LingBot World 2, X2, LTX were missing/renamed), plus create-reactor-app and the @reactor-models/<model> typed-per-model-SDK pointer, pulled from the current docs site.

Test plan

• Every claim cross-checked against reactor-client-sdks' actual sdks/js/src and sdks/python/reactor_sdk source (constructor signatures, method lists, event names, error class hierarchies), not inferred from names or old docs.
• Docs-only change — no build/test surface in this repo.