Register Time Travel on Agent Zero's existing /a0/usr watchdog and coalesce automatic snapshot triggers into a single pending commit window capped at one commit per workspace every 10 seconds.
Exclude top-level /a0/usr plugins and nested Git worktrees from root snapshots, preserve self-root Git workspace tracking, and cover the behavior with Time Travel tests.
Add the _time_travel core plugin with Agent Zero-owned shadow Git snapshots, history/diff/preview/travel/revert APIs, capture hooks, and canvas plus floating window UI surfaces for /a0/usr workspaces.
Wire generic file-browser mutation hooks for UI edits, update modal backdrop handling, remove the legacy _diff_viewer plugin, and replace Diff Viewer tests with focused Time Travel coverage.
Inspired by Space Agent :-)
