Add Muse Glimmer local voice agent for macOS

[seyeong-han]

Summary

Adds the complete Muse Glimmer local voice-agent application under muse_glimmer/macos for macOS on Apple silicon. The browser, loopback-only LiveKit server, token service, LiveKit worker, Parakeet ASR adapter, Muse Glimmer LLM integration, and persistent Supertonic TTS adapter are included as source with one-command development tooling.

The import is based on standalone source snapshot 914fb816fe9e0f6b7fc808fd843eb2e97df31dcf. Product-owned source is relicensed to BSD-3-Clause for canonical maintenance in meta-pytorch/executorch-examples; independent model, font, LiveKit, ExecuTorch, and other third-party terms remain documented separately.

Review guide

• Application lifecycle and release gates: muse_glimmer/macos/README.md, muse_glimmer/macos/Makefile, muse_glimmer/macos/scripts/
• Voice worker and privacy/reporting: muse_glimmer/macos/apps/worker/
• ExecuTorch LiveKit ASR/TTS adapters: muse_glimmer/macos/packages/livekit-plugins-executorch/
• Local web experience: muse_glimmer/macos/apps/web/
• Artifact and compatibility contracts: muse_glimmer/macos/artifacts/, muse_glimmer/macos/config/dependencies/
• Licensing/provenance: muse_glimmer/macos/LICENSE, muse_glimmer/macos/PROVENANCE.md, muse_glimmer/macos/THIRD_PARTY_NOTICES.md
• Path-scoped CI: .github/workflows/muse-glimmer-macos.yml

Compatibility state

• ExecuTorch #22063 has landed at 81969a92dd2e5515fa23ccdf9d87346cf3ba2ba2.
• ExecuTorch #22070 landed at 5bd86e50fcd986999e4c09b82de040a3ba224466.
• ExecuTorch #22208 adds persistent Supertonic --server_jsonl mode and is pending review.
• Its protocol-v1 ready frame includes sample_rate: 44100, matching the strict adapter contract.
• The final ExecuTorch compatibility commit remains null and ready_for_release remains false.

The release gate is intentionally closed. Release readiness requires every capability to land, one verified descendant ExecuTorch commit, matching revisions for all ExecuTorch-built artifacts, complete artifact provenance/checksums/licenses, and a clean-machine end-to-end run.

Validation

• Python: 115 passed, 1 intentionally skipped model-heavy E2E test
• Web: 30 Vitest tests and 5 Node server tests passed
• Ruff, Prettier, ESLint, and TypeScript checks passed
• Manifest and subtree publication scans passed for 125 tracked files
• All three Python packages built as wheel and sdist with verified BSD LICENSE payloads and no obsolete NOTICE payloads
• Browser bundle privacy scan passed
• npm audit --audit-level=high: 0 vulnerabilities

Expected local warning: Starlette/FastAPI TestClient deprecation. The model-heavy E2E test remains skipped until the final ExecuTorch compatibility pin and prepared artifacts exist.