release: ShuffleMuse v0.1.2

[ColderCoder]

Summary

• add Browse folder playback that prepends direct audio files without duplicating or discarding the remaining randomized queue
• preserve the optimized Original response copy path and reduce idle or hidden-page status polling
• add cancellable playback intents and a best-effort 15-second Web Audio endpoint keepalive without a fixed startup delay
• refine Home and intermediate-width player layouts
• update release metadata and documentation for v0.1.2

Validation

• go mod verify
• go test -count=1 ./...
• go test -race -count=1 ./...
• go vet ./...
• bun install --frozen-lockfile
• bun run test:run (17 files, 82 tests)
• bun run build
• all three Docker Compose configurations
• exact-version Docker image identity, non-root user, and hardened runtime smoke test
• real 68-track library: Original Range, Opus, seek, pause/resume, track changes, and folder queueing
• isolated Chromium responsive and low-bandwidth playback checks

Audio endpoint scope

The fixed 1.5-second warmup delay is removed. Endpoint activation and the 15-second post-pause keepalive are best-effort fallbacks and do not block HTML media playback. Physical Bluetooth or HDMI endpoint behavior still requires device testing.