Summary

• Add a shared realtime voice output activity tracker to the SDK for audio counters, stream-ending/playback state, interruptible-output checks, and playback watchdog timing.
• Migrate Discord realtime voice playback/barge-in bookkeeping onto the shared tracker while leaving transport, audio conversion, stream/player lifecycle, and Discord config local.
• Refresh SDK API baseline plus realtime voice SDK docs and changelog.

Verification

• pnpm exec oxfmt --check --threads=1 src/talk/output-activity-tracker.ts src/talk/output-activity-tracker.test.ts src/plugin-sdk/realtime-voice.ts extensions/discord/src/voice/realtime.ts
• node scripts/run-vitest.mjs src/talk/output-activity-tracker.test.ts
• pnpm test extensions/discord/src/voice/manager.e2e.test.ts -- --reporter=dot -t "allows configured realtime barge-in|interrupts realtime playback when an already-active speaker keeps talking|does not interrupt realtime provider state when local playback is already idle|ignores realtime capture during playback when barge-in is disabled|queues forced agent-proxy answers until current realtime playback idles|does not interrupt active exact speech for a later forced agent-proxy consult|drains queued exact speech after cancelled prebuffered output is discarded"
• pnpm plugin-sdk:api:check
• pnpm build
• env -u OPENCLAW_TESTBOX pnpm check:changed
• /Users/steipete/Projects/agent-skills/skills/autoreview/scripts/autoreview --mode local

Behavior addressed: Discord realtime output playback and barge-in decisions now use the same provider/channel-neutral activity tracker that browser and meeting-style realtime surfaces can reuse.
Real environment tested: Local macOS source checkout, Node/pnpm repo toolchain, focused Discord realtime voice adapter tests.
Exact steps or command run after this patch: Focused tracker tests, focused Discord voice manager e2e tests listed above, SDK API check, full build, changed checks, and autoreview.
Evidence after fix: Tracker tests passed, seven Discord realtime voice e2e cases passed, SDK API baseline check passed, build passed, check:changed passed, autoreview reported no accepted/actionable findings.
Observed result after fix: No intended live provider behavior change; Discord kept local playback/audio lifecycle ownership while shared state produced the same barge-in and playback-idle semantics under adapter tests.
What was not tested: Live Discord, browser voice, or Google Meet-style provider sessions; this is a pure helper extraction with unit and adapter proof.