LanMountainDesktop/.trae/specs/pdc-incremental-migration/spec.md

PDC Incremental Update Migration

Goal

Replace VeloPack-based incremental packaging with a unified signed FileMap pipeline and prepare for PDC/S3 distribution compatibility, while keeping Launcher installation, rollback, and update orchestration ownership unchanged.

Stage 1 (Completed in this round)

• Release workflow outputs signed FileMap incremental assets as the primary path:
  • files-windows-x64.json / .sig / update-windows-x64.zip
  • files-windows-x86.json / .sig / update-windows-x86.zip
  • files-linux-x64.json / .sig / update-linux-x64.zip
• Launcher and host update runtime remove VeloPack branches and return to signed FileMap apply path.
• Host update asset discovery supports platform-scoped names with fallback to legacy generic names.
• Optional S3 sync publishes incremental assets in parallel with GitHub Release assets.

Stage 2 (In Progress)

• Introduce PDC-compatible update source (pdc) with fallback to GitHub.
• Add PDC metadata/latest/distribution API consumption abstraction.
• Keep Launcher install/apply/rollback state machine unchanged.
• Prepare phainon.yml-compatible release metadata for future PDCC integration.

Acceptance

• release.yml no longer contains VeloPack packaging steps.
• Windows x64/x86 and Linux x64 release jobs all upload signed FileMap incremental assets.
• Host auto-update can detect and download platform-matching signed FileMap assets.
• Launcher update apply succeeds with signed FileMap payload and rollback behavior remains unchanged.
• Optional S3 upload step works when S3 secrets/vars are configured.