Add session forking capability (#5882)

Co-authored-by: Zane Staggs <zane@squareup.com>

ui/desktop/src/api/types.gen.ts

@@ -189,17 +189,6 @@ export type DetectProviderResponse = {
     provider_name: string;
 };
 
-export type EditMessageRequest = {
-    editType?: EditType;
-    timestamp: number;
-};
-
-export type EditMessageResponse = {
-    sessionId: string;
-};
-
-export type EditType = 'fork' | 'edit';
-
 export type EmbeddedResource = {
     _meta?: {
         [key: string]: unknown;
@@ -352,6 +341,16 @@ export type ExtensionResponse = {
     warnings?: Array<string>;
 };
 
+export type ForkRequest = {
+    copy: boolean;
+    timestamp?: number | null;
+    truncate: boolean;
+};
+
+export type ForkResponse = {
+    sessionId: string;
+};
+
 export type FrontendToolRequest = {
     id: string;
     toolCall: {
@@ -3178,46 +3177,6 @@ export type GetSessionResponses = {
 
 export type GetSessionResponse = GetSessionResponses[keyof GetSessionResponses];
 
-export type EditMessageData = {
-    body: EditMessageRequest;
-    path: {
-        /**
-         * Unique identifier for the session
-         */
-        session_id: string;
-    };
-    query?: never;
-    url: '/sessions/{session_id}/edit_message';
-};
-
-export type EditMessageErrors = {
-    /**
-     * Bad request - Invalid message timestamp
-     */
-    400: unknown;
-    /**
-     * Unauthorized - Invalid or missing API key
-     */
-    401: unknown;
-    /**
-     * Session or message not found
-     */
-    404: unknown;
-    /**
-     * Internal server error
-     */
-    500: unknown;
-};
-
-export type EditMessageResponses = {
-    /**
-     * Session prepared for editing - frontend should submit the edited message
-     */
-    200: EditMessageResponse;
-};
-
-export type EditMessageResponse2 = EditMessageResponses[keyof EditMessageResponses];
-
 export type ExportSessionData = {
     body?: never;
     path: {
@@ -3290,6 +3249,46 @@ export type GetSessionExtensionsResponses = {
 
 export type GetSessionExtensionsResponse = GetSessionExtensionsResponses[keyof GetSessionExtensionsResponses];
 
+export type ForkSessionData = {
+    body: ForkRequest;
+    path: {
+        /**
+         * Unique identifier for the session
+         */
+        session_id: string;
+    };
+    query?: never;
+    url: '/sessions/{session_id}/fork';
+};
+
+export type ForkSessionErrors = {
+    /**
+     * Bad request - truncate=true requires timestamp
+     */
+    400: unknown;
+    /**
+     * Unauthorized - Invalid or missing API key
+     */
+    401: unknown;
+    /**
+     * Session not found
+     */
+    404: unknown;
+    /**
+     * Internal server error
+     */
+    500: unknown;
+};
+
+export type ForkSessionResponses = {
+    /**
+     * Session forked successfully
+     */
+    200: ForkResponse;
+};
+
+export type ForkSessionResponse = ForkSessionResponses[keyof ForkSessionResponses];
+
 export type UpdateSessionNameData = {
     body: UpdateSessionNameRequest;
     path: {