feat: session manger (#867)

* feat: init session manger

* feat: persist selected app to localStorage

- Save app selection when switching providers
- Restore last selected app on page load

* feat: persist current view to localStorage

- Save view selection when switching tabs
- Restore last selected view on page load

* styles: update ui

* feat: Improve macOS Terminal activation and refactor Kitty launch to use  command with user's default shell.

* fix: session view

* feat: toc

* feat: Implement FlexSearch for improved session search functionality.

* feat: Redesign session manager search and filter UI for a more compact and dynamic experience.

* refactor: modularize session manager by extracting components and utility functions into dedicated files.

* feat: Enhance session terminal launching with support for iTerm2, Ghostty, WezTerm, and Alacritty, including UI and custom configuration options.

* feat: Conditionally render terminal selection and resume session buttons only on macOS.

src/lib/api/index.ts

@@ -7,6 +7,7 @@ export { skillsApi } from "./skills";
 export { usageApi } from "./usage";
 export { vscodeApi } from "./vscode";
 export { proxyApi } from "./proxy";
+export { sessionsApi } from "./sessions";
 export * as configApi from "./config";
 export type { ProviderSwitchEvent } from "./providers";
 export type { Prompt } from "./prompts";