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/lib/oauth/constants/oauth.js

@@ -142,6 +142,34 @@ export const KIRO_CONFIG = {
   authMethods: ["builder-id", "idc", "google", "github", "import"],
 };
 
+// Cursor OAuth Configuration (Import Token from Cursor IDE)
+// Cursor stores credentials in SQLite database: state.vscdb
+// Keys: cursorAuth/accessToken, storage.serviceMachineId
+export const CURSOR_CONFIG = {
+  // API endpoints
+  apiEndpoint: "https://api2.cursor.sh",
+  chatEndpoint: "/aiserver.v1.ChatService/StreamUnifiedChatWithTools",
+  modelsEndpoint: "/aiserver.v1.AiService/GetDefaultModelNudgeData",
+  // Additional endpoints
+  api3Endpoint: "https://api3.cursor.sh", // Telemetry
+  agentEndpoint: "https://agent.api5.cursor.sh", // Privacy mode
+  agentNonPrivacyEndpoint: "https://agentn.api5.cursor.sh", // Non-privacy mode
+  // Client metadata
+  clientVersion: "0.48.6",
+  clientType: "ide",
+  // Token storage locations (for user reference)
+  tokenStoragePaths: {
+    linux: "~/.config/Cursor/User/globalStorage/state.vscdb",
+    macos: "~/Library/Application Support/Cursor/User/globalStorage/state.vscdb",
+    windows: "%APPDATA%\\Cursor\\User\\globalStorage\\state.vscdb",
+  },
+  // Database keys
+  dbKeys: {
+    accessToken: "cursorAuth/accessToken",
+    machineId: "storage.serviceMachineId",
+  },
+};
+
 // OAuth timeout (5 minutes)
 export const OAUTH_TIMEOUT = 300000;
 
@@ -156,4 +184,5 @@ export const PROVIDERS = {
   OPENAI: "openai",
   GITHUB: "github",
   KIRO: "kiro",
+  CURSOR: "cursor",
 };