lanspread/organize/decision-tracking/IMPL_DECISIONS.md

Implementation Decisions

• Added a just test recipe so unit tests can be run through the repository's required just ... command surface instead of invoking cargo test directly.
• Renamed the frontend success event to game-install-finished; the old unpack name no longer matched the transactional install/update lifecycle.
• Implemented watcher rescans by reusing the app-state local_library/index.json cache and updating a single game entry in that index. This satisfies the per-ID optimized rescan requirement without adding a second cache format.
• Split full startup recovery from ordinary settled refreshes. Startup and real SetGameDir changes run recovery plus a scan; install/update/uninstall completion only rescans the affected game after operation tracking has been cleared.
• Rejected path-changing SetGameDir while operations are active. Same-path refreshes are allowed and deliberately skip full recovery so they cannot sweep download transients for in-flight work.
• Kept a separate active_downloads cancellation-token map next to the single active_operations table. The operation table is the authoritative state for gates; the token map is only cancellation plumbing for in-flight downloads.
• Treated a downloaded-but-not-installed game as immediately installable from Tauri by sending PeerCommand::InstallGame directly. A not-downloaded game uses PeerCommand::DownloadGameFiles; the peer derives every path, size, and hash from its local catalog manifest and auto-installs after the sentinel commit.
• Removed the dead internal PeerCommand::UpdateGame path. The UI update button now sends the same exact-content download command. The local catalog remains descriptor authority, and only authenticated peers advertising its exact ContentId are eligible sources before the normal update transaction runs.
• Removed the unreachable Availability::Downloading protocol value. Active operations are reported separately, and local summaries emit only settled availability.
• Threaded availability through the UI-facing Game payload so LocalOnly rendering follows backend state instead of reverse-engineering it from installed && !downloaded.
• Removed Tauri's parallel whole-library filesystem scan. The UI database keeps bundled catalog metadata, while peer LocalLibraryChanged snapshots now own downloaded, installed, local_version, and availability.