…ub Copilot builds

…t#248)

)

…state (microsoft#164)

- Synchronize all extMcpInfoMap accesses on the manager monitor so the
  HashMap is never iterated/mutated concurrently by the async
  doRegistration() worker, the contribution-point-policy event handler,
  and the UI-thread approval flow.
- approveExtMcpRegistration() now snapshots the map under the lock and
  opens McpApprovalDialog outside the lock so the worker is not stalled
  while the user interacts; post-dialog reconciliation re-acquires the
  lock and the LSP-pushing event publish runs outside the lock.
- Mark approvedExtMcpServers volatile and make hasExtMcpRegistration()
  synchronized for consistent visibility from the UI thread.
- Avoid pre-populating in-memory approved servers from the persisted
  cache at startup; let doRegistration() refresh state and fire
  TOPIC_MCP_EXTENSION_POINT_REGISTRATION_COMPLETED so the LSP receives
  the verified set instead of stale data (uninstalled plugin, changed
  port, removed server).
- Fix bundle-state guard in loadMcpRegistrationExtensionPoint() (|| ->
  &&) so already-active or starting bundles are not pointlessly started
  again.
- LanguageServerSettingManager subscribes to the new completion topic
  and exposes an overload that accepts the approved JSON directly,
  avoiding the ChatServiceManager lookup from early-startup paths.
- Add regression tests covering plugin uninstall, config change
  (re-approval required), and unchanged config (approval carry-over).

Issue: microsoft#153
---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: xinyi-gong <torigong@microsoft.com>

…references (microsoft#256)