feat: keyboard shortcuts for agent manager tab/worktree management (#495)

* feat: add keyboard shortcuts for agent manager tab/worktree management

* fix: use mock.module in git-context tests to avoid cross-file mock leakage

* feat: shared worktree delete confirmation dialog with Enter/Esc, Cmd+W fallthrough, Cmd+T race fix

* fix: Enter on delete dialog, VS Code theme colors, Cmd+N auto-switch, shortcut hints, smooth neighbor selection on worktree delete

* refactor: move confirm dialog styles to kilo-ui, replace 'local' magic string with LOCAL constant

* revert: restore upstream commit-message tests, drop our git.ts/GitRunner changes

* revert: remove out-of-scope kilo-ui/SessionList/chat.css changes, keep confirm styles in agent-manager.css

* fix: remove stale /P reference from comment

* fix: move keybinding entries from submenus to keybindings array