feat(sessions): add open-in-new-window menu action

[Chloe-JY]

Problem

Session sidebar context menus expose destinations such as a new tab and My Station, but they do not expose the detached window behavior that already exists in session headers. This affects supported local session rows and Team Conversation rows. The root cause is that both native menu builders stop at their tab and station handlers and never dispatch to openSessionInNewWindowAtom.

Solution

Add Open in New Window immediately after Open in New Tab in the local and Team Conversation native menus. Local rows dispatch through the existing detached-window atom so successful opens retain its tab-ownership behavior and failed opens preserve the current tabs. Team Conversation rows reuse the existing replay/import destination resolver and pass the resolved local session id to the same detached-window path. Focused regression tests cover the menu entry and callback for regular local, Cursor import, terminal, and team-session menu variants.

Potential risks

Remote Team Conversations still depend on the existing replay/import lifecycle before the detached surface can load the local replay, and native window creation remains platform-dependent. Failures use the existing visible error path and do not close current tabs. No dependency, persistence, data migration, configuration, public API, IPC, or wire-format changes are included, so rollback is limited to reverting this commit. The native desktop menu was not manually exercised or captured because local computer control was not authorized; menu ordering is verified at the native-menu option boundary.

Verification

• pnpm test -- --run src/scaffold/NavigationSidebar/connectors/tests/useWorkstationSidebarContextMenu.test.ts src/scaffold/NavigationSidebar/connectors/WorkstationSidebarConnector/cloudSessionNativeMenuItems.test.ts — passed, 2 files and 2 tests
• pnpm typecheck — passed
• pnpm exec eslint on all 10 changed TypeScript files with --max-warnings 0 --report-unused-disable-directives — passed
• pnpm lint:fast — passed
• pnpm check:circular — passed, no circular dependencies across 6452 modules
• pnpm check:test-placement — passed, consistent across 456 directories
• git diff --check origin/develop...HEAD — passed
• Commit hooks — lint-staged, Oxlint, ESLint fix, Prettier, and staged TypeScript checks passed
• Not run: native desktop screenshot or recording; computer-control permission was not provided