feat(core): pass resolved plan directory context to tools and system prompt via activeExtensionName

packages/core/src/config/agent-loop-context.ts

@@ -26,6 +26,9 @@ export interface AgentLoopContext {
   /** The unique ID for the parent session if this is a subagent. */
   readonly parentSessionId?: string;
 
+  /** The name of the active extension driving this context, if any. */
+  readonly activeExtensionName?: string;
+
   /** The registry of tools available to the agent in this context. */
   readonly toolRegistry: ToolRegistry;
 

packages/core/src/config/config.ts

@@ -737,6 +737,17 @@ export class Config implements McpContext, AgentLoopContext {
   private blockedEnvironmentVariables: string[];
   private readonly enableEnvironmentVariableRedaction: boolean;
   private _promptRegistry!: PromptRegistry;
+  private _activeExtensionName?: string;
+
+  get activeExtensionName(): string | undefined {
+    return (
+      this._activeExtensionName || process.env['GEMINI_CLI_ACTIVE_EXTENSION']
+    );
+  }
+
+  setActiveExtensionName(name: string | undefined): void {
+    this._activeExtensionName = name;
+  }
   private _resourceRegistry!: ResourceRegistry;
   private agentRegistry!: AgentRegistry;
   private readonly acknowledgedAgentsService: AcknowledgedAgentsService;