fix(workspace): allow removing missing workspace repos from UI (#2234) - #2253

Summary

Closes #2234

When a workspace member directory is removed or renamed on disk:

1. The server creates a synthetic repo entry with status: "missing_dir" and ID ws:<alias>.
2. The UI sidebar tells users to open the Workspace page to remove or fix it, but the Workspace page rendered no action buttons for missing_dir rows.
3. No API endpoint existed to remove workspace configuration entries, and calling DELETE /api/repos/ws:<alias> returned a 404 database error.
4. Removing via the CLI (repowise workspace remove <alias>) was not reflected in running repowise serve instances because in-memory workspace_config was only loaded at startup.

Changes Made

• Server Endpoints & Live State Sync:

  • Added DELETE /api/workspace/repos/{alias} in routers/workspace.py to drop the entry from .repowise-workspace.yaml and save the file to disk.
  • Live reload request.app.state.workspace_config and clean up workspace_sessions, workspace_fts, workspace_path_to_repo_id, and workspace_vector_stores caches so the running server immediately reflects the removal without requiring a restart.
  • Added synthetic ws:<alias> ID handling in DELETE /api/repos/{repo_id} (routers/repos.py) to delegate cleanly to workspace configuration removal.
  • Added and re-exported WorkspaceRepoRemovedResponse schema.

• API Client:

  • Added removeWorkspaceRepo(alias) to packages/api-client/src/workspace.ts and exported WorkspaceRepoRemovedResponse interface.

• Web UI:

  • Added RemoveWorkspaceRepoButton component in packages/web/src/app/workspace/sync-buttons.tsx.
  • Wired actionsFor in packages/web/src/app/workspace/page.tsx to display the "Remove" button when repo.status === "missing_dir".

• Unit Tests:

  • Added tests/unit/server/test_workspace_remove_repo.py covering:
    • Successful removal and persistence to .repowise-workspace.yaml
    • Live in-memory state and cache cleanup
    • 404 response for unknown alias
    • 404 response outside workspace mode
    • Synthetic DELETE /api/repos/ws:<alias> deletion

Verification

• Ran full workspace test suite (74 tests passed):
  pytest tests/unit/server/test_workspace_router.py tests/unit/server/test_workspace_remove_repo.py tests/unit/server/test_workspace_sidebar.py
• Verified TypeScript builds without errors.