[sshcrack]

Full-quality desktop playback loses frames when a visible live preview requests hardware readback. On the deployed Pi, this change keeps the same Metablob scene near 60 presentation FPS with preview active while preserving the exact GPIO bitplanes.

• Consume published rpi-rgb-led-matrix v0.1.12, released from the actual library checkout through library PR #11. The grouped converter, lazy exact inverse-color lookups, Windows compatibility fix and hardware equivalence tests live there. Both app overlay patches are removed.
• Route offload, video, shader streams and AudioKit buffers through the library's packed-RGB bulk converter. Brightness, gamma, RGB ordering, PWM depth, mapper behavior and visual output are preserved.
• Keep automatic preview strictly viewer-driven, coalesced and inactive while hidden; idle sockets do no capture work.
• Update a reused worker session's target FPS without restarting its scene, timeline, sequence or transition. The optional state field remains compatible with protocol 4; updated desktop workers gain the rate correction.
• Pace Pi frames against absolute fractional deadlines, filling only the remainder left by VSync and skipping missed slots after stalls.

Validation against the published library release:

• Full emulator build: 51 tests passed, including visual regressions and preview demand coverage.
• Full Linux desktop build: 48 tests passed, including worker rendering, state continuity and saved contract fixtures.
• ARM build passed. Library hardware/SDL configurations passed 5/8 tests; its native Windows emulator and both Python configurations passed CI before release.
• Hardware bitplane equivalence and the original readback fingerprint were verified on the laptop and Pi with the same library conversion code.
• Controlled Pi A/B/A trials, about 30 seconds per condition, desktop placement and quality 1.0 throughout retained samples:
  • No preview: installed 58.66–58.72 FPS; candidate 59.81 FPS.
  • Automatic preview: installed 53.26–53.36 FPS; candidate 59.96 FPS.
  • Daemon CPU reduced about 7.7%; throttling remained 0x0 at 1.2 GHz.
• Isolated Pi RGB blits: 7.226 ms scalar → 4.428 ms bulk; requested readback: 11.760 → 7.020 ms.
• Presentation counts can include repeated fresh remote frames; these averages do not establish 60 unique, evenly spaced frames per second. Preliminary runs with incomplete plugin upload or a placement change were excluded.

See docs/pi-frame-pacing.md for measurements and test details. The installed service, original 13 presets and Automatic Mode were restored after benchmarking.

Screenshots and scene preview GIF regeneration are skipped: this changes performance and scheduling, with byte-identical panel output and no UI, scene look or default property change. Build outputs, profiles and benchmark artifacts are not committed.

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📦 Build artifacts

Built from 2580dae · CI run

Platform	Download	Archive size
desktop-linux-build	Download	263 MiB
desktop-windows-build	Download	40 MiB
led-matrix-build	Download	356 MiB
web-build	Download	0 MiB