Summary

This PR fixes a narrator speech regression introduced while restoring briefing video audio in commit c0ce9f0.

Mission intro speech and victory narration were silently dropped on OpenAL builds because generic AT_Streaming streams could be refilled during update() but still remain stopped in the same frame, then get released by processPlayingList() before playback starts.

Root Cause

• OpenAL stream lifecycle logic was hardened for video timing.
• Generic speech streams have a different producer lifecycle from video streams.
• After in-frame refill, stopped state could persist until teardown check.

Fix

• Add a post-refill restart check in OpenALAudioStream::update() when source is AL_STOPPED/AL_INITIAL/AL_PAUSED and queued buffers are present.
• Keep the existing video audio restoration path intact.

Validation

• User confirmed end-to-end behavior: videos remain working and narrator speech is restored.
• Editor diagnostics are clean for touched files.

Notes

• Dev diary updated in docs/DEV_BLOG/2026-04-DIARY.md.
• Lessons learned updated in docs/WORKDIR/lessons/2026-04-LESSONS.md.

Related-to #38