Bring in the selected-workspace filesystem access fix from the detached
investigation worktree so Windows projects outside the user home can use
desktop @ file search.
Constraint: Preserve local main history while landing the detached worktree fix
Confidence: high
Scope-risk: moderate
Tested: bun test src/server/__tests__/filesystem.test.ts
Tested: bun run check:server
Not-tested: Windows packaged desktop smoke after merge