feat(cursor): Integrate Cursor IDE support with OAuth import token flow

- Add CursorExecutor for handling requests to the Cursor API using protobuf over HTTP/2.
- Implement CursorAuthModal for user token import from local SQLite database.
- Update provider models and constants to include Cursor as a supported provider.
- Enhance API service with token validation and user info extraction from Cursor tokens.
- Introduce utility functions for checksum generation and protobuf encoding/decoding for Cursor API interactions.

src/shared/constants/providers.js

@@ -10,6 +10,7 @@ export const OAUTH_PROVIDERS = {
   "gemini-cli": { id: "gemini-cli", alias: "gc", name: "Gemini CLI", icon: "terminal", color: "#4285F4" },
   github: { id: "github", alias: "gh", name: "GitHub Copilot", icon: "code", color: "#333333" },
   kiro: { id: "kiro", alias: "kr", name: "Kiro AI", icon: "psychology_alt", color: "#FF6B35" },
+  cursor: { id: "cursor", alias: "cu", name: "Cursor IDE", icon: "edit_note", color: "#00D4AA" },
 };
 
 export const APIKEY_PROVIDERS = {