feat(extensions): add plan directory support to gemini-extension.json

packages/cli/src/config/extension-manager.ts

@@ -862,6 +862,7 @@ Would you like to attempt to install via "git clone" instead?`,
         installMetadata,
         mcpServers: config.mcpServers,
         excludeTools: config.excludeTools,
+        plan: config.plan,
         hooks,
         isActive: this.extensionEnablementManager.isEnabled(
           config.name,

packages/cli/src/config/extension.ts

@@ -28,6 +28,7 @@ export interface ExtensionConfig {
   contextFileName?: string | string[];
   excludeTools?: string[];
   settings?: ExtensionSetting[];
+  plan?: { directory?: string };
   /**
    * Custom themes contributed by this extension.
    * These themes will be registered when the extension is activated.

packages/core/src/config/config.ts

@@ -308,6 +308,7 @@ export interface GeminiCLIExtension {
   mcpServers?: Record<string, MCPServerConfig>;
   contextFiles: string[];
   excludeTools?: string[];
+  plan?: PlanSettings;
   id: string;
   hooks?: { [K in HookEventName]?: HookDefinition[] };
   settings?: ExtensionSetting[];