fix(core): migrate consumers to lazily-evaluated getPlansDir

Updates prompts and tool implementations (edit, write-file, enter/exit plan mode) to route through Config.getPlansDir() instead of Storage.getPlansDir(). This ensures the plan directory is lazily created exactly when these features attempt to use it, preventing ENOENT failures.

packages/core/src/core/__snapshots__/prompts.test.ts.snap

@@ -572,7 +572,7 @@ For example:
 
 # Active Approval Mode: Plan
 
-You are operating in **Plan Mode**. Your goal is to produce an implementation plan in \`/tmp/project-temp/plans/\` and get user approval before editing source code.
+You are operating in **Plan Mode**. Your goal is to produce an implementation plan in \`/tmp/plans/\` and get user approval before editing source code.
 
 ## Available Tools
 The following tools are available in Plan Mode:
@@ -588,8 +588,8 @@ The following tools are available in Plan Mode:
 </available_tools>
 
 ## Rules
-1. **Read-Only:** You cannot modify source code. You may ONLY use read-only tools to explore, and you can only write to \`/tmp/project-temp/plans/\`. If the user asks you to modify source code directly, you MUST explain that you are in Plan Mode and must first create a plan and get approval.
-2. **Write Constraint:** \`write_file\` and \`replace\` may ONLY be used to write .md plan files to \`/tmp/project-temp/plans/\`. They cannot modify source code.
+1. **Read-Only:** You cannot modify source code. You may ONLY use read-only tools to explore, and you can only write to \`/tmp/plans/\`. If the user asks you to modify source code directly, you MUST explain that you are in Plan Mode and must first create a plan and get approval.
+2. **Write Constraint:** \`write_file\` and \`replace\` may ONLY be used to write .md plan files to \`/tmp/plans/\`. They cannot modify source code.
 3. **Efficiency:** Autonomously combine discovery and drafting phases to minimize conversational turns. If the request is ambiguous, use \`ask_user\` to clarify. Use multi-select to offer flexibility and include detailed descriptions for each option to help the user understand the implications of their choice.
 4. **Inquiries and Directives:** Distinguish between Inquiries and Directives to minimize unnecessary planning.
    - **Inquiries:** If the request is an **Inquiry** (e.g., "How does X work?"), answer directly. DO NOT create a plan.
@@ -612,7 +612,7 @@ The depth of your consultation should be proportional to the task's complexity.
 **CRITICAL:** You MUST NOT proceed to Step 3 (Draft) or Step 4 (Review & Approval) in the same turn as your initial strategy proposal. You MUST wait for user feedback and reach a clear agreement before drafting or submitting the plan.
 
 ### 3. Draft
-Write the implementation plan to \`/tmp/project-temp/plans/\`. The plan's structure adapts to the task:
+Write the implementation plan to \`/tmp/plans/\`. The plan's structure adapts to the task:
 - **Simple Tasks:** Include a bulleted list of specific **Changes** and **Verification** steps.
 - **Standard Tasks:** Include an **Objective**, **Key Files & Context**, **Implementation Steps**, and **Verification & Testing**.
 - **Complex Tasks:** Include **Background & Motivation**, **Scope & Impact**, **Proposed Solution**, **Alternatives Considered**, a phased **Implementation Plan**, **Verification**, and **Migration & Rollback** strategies.

packages/core/src/core/prompts.test.ts

@@ -90,9 +90,10 @@ describe('Core System Prompt (prompts.ts)', () => {
       getToolRegistry: vi.fn().mockReturnValue(mockRegistry),
       getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
       getSandboxEnabled: vi.fn().mockReturnValue(false),
+      getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
       storage: {
         getProjectTempDir: vi.fn().mockReturnValue('/tmp/project-temp'),
-        getPlansDir: vi.fn().mockReturnValue('/tmp/project-temp/plans'),
+        getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
         getProjectTempTrackerDir: vi
           .fn()
           .mockReturnValue('/mock/.gemini/tmp/session/tracker'),
@@ -423,6 +424,7 @@ describe('Core System Prompt (prompts.ts)', () => {
         getToolRegistry: vi.fn().mockReturnValue(mockToolRegistry),
         getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
         getSandboxEnabled: vi.fn().mockReturnValue(false),
+        getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
         storage: {
           getProjectTempDir: vi.fn().mockReturnValue('/tmp/project-temp'),
         },

packages/core/src/prompts/promptProvider.test.ts

@@ -61,6 +61,7 @@ describe('PromptProvider', () => {
       topicState: new TopicState(),
       getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
       getSandboxEnabled: vi.fn().mockReturnValue(false),
+      getPlansDir: vi.fn().mockReturnValue('/tmp/project-temp/plans'),
       storage: {
         getProjectTempDir: vi.fn().mockReturnValue('/tmp/project-temp'),
         getPlansDir: vi.fn().mockReturnValue('/tmp/project-temp/plans'),

packages/core/src/prompts/promptProvider.ts

@@ -188,7 +188,7 @@ export class PromptProvider {
           () => ({
             interactive: interactiveMode,
             planModeToolsList,
-            plansDir: context.config.storage.getPlansDir(),
+            plansDir: context.config.getPlansDir(),
             approvedPlanPath: context.config.getApprovedPlanPath(),
           }),
           isPlanMode,

packages/core/src/tools/edit.test.ts

@@ -132,9 +132,10 @@ describe('EditTool', () => {
       getDisableLLMCorrection: vi.fn(() => true),
       getExperiments: () => {},
       isPlanMode: vi.fn(() => false),
+      getPlansDir: vi.fn().mockReturnValue('/tmp/project/plans'),
       storage: {
         getProjectTempDir: vi.fn().mockReturnValue('/tmp/project'),
-        getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
+        getPlansDir: vi.fn().mockReturnValue('/tmp/project/plans'),
       },
       isPathAllowed(this: Config, absolutePath: string): boolean {
         const workspaceContext = this.getWorkspaceContext();
@@ -1314,6 +1315,7 @@ function doIt() {
       fs.mkdirSync(plansDir);
 
       vi.mocked(mockConfig.isPlanMode).mockReturnValue(true);
+      vi.mocked(mockConfig.getPlansDir).mockReturnValue(plansDir);
       vi.mocked(mockConfig.storage.getPlansDir).mockReturnValue(plansDir);
 
       const filePath = path.join(rootDir, 'test-file.txt');

packages/core/src/tools/edit.ts

@@ -465,10 +465,7 @@ class EditToolInvocation
     );
     if (this.config.isPlanMode()) {
       const safeFilename = path.basename(this.params.file_path);
-      this.resolvedPath = path.join(
-        this.config.storage.getPlansDir(),
-        safeFilename,
-      );
+      this.resolvedPath = path.join(this.config.getPlansDir(), safeFilename);
     } else if (!path.isAbsolute(this.params.file_path)) {
       const result = correctPath(this.params.file_path, this.config);
       if (result.success) {

packages/core/src/tools/enter-plan-mode.test.ts

@@ -11,7 +11,6 @@ import type { Config } from '../config/config.js';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
 import { ToolConfirmationOutcome } from './tools.js';
 import { ApprovalMode } from '../policy/types.js';
-import fs from 'node:fs';
 
 vi.mock('node:fs', async () => {
   const actual = await vi.importActual<typeof import('node:fs')>('node:fs');
@@ -39,6 +38,7 @@ describe('EnterPlanModeTool', () => {
 
     mockConfig = {
       setApprovalMode: vi.fn(),
+      getPlansDir: vi.fn().mockReturnValue('/mock/plans/dir'),
       storage: {
         getPlansDir: vi.fn().mockReturnValue('/mock/plans/dir'),
       } as unknown as Config['storage'],
@@ -119,7 +119,6 @@ describe('EnterPlanModeTool', () => {
   describe('execute', () => {
     it('should set approval mode to PLAN and return message', async () => {
       const invocation = tool.build({});
-      vi.mocked(fs.existsSync).mockReturnValue(true);
 
       const result = await invocation.execute(new AbortController().signal);
 
@@ -130,21 +129,9 @@ describe('EnterPlanModeTool', () => {
       expect(result.returnDisplay).toBe('Switching to Plan mode');
     });
 
-    it('should create plans directory if it does not exist', async () => {
-      const invocation = tool.build({});
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      await invocation.execute(new AbortController().signal);
-
-      expect(fs.mkdirSync).toHaveBeenCalledWith('/mock/plans/dir', {
-        recursive: true,
-      });
-    });
-
     it('should include optional reason in output display but not in llmContent', async () => {
       const reason = 'Design new database schema';
       const invocation = tool.build({ reason });
-      vi.mocked(fs.existsSync).mockReturnValue(true);
 
       const result = await invocation.execute(new AbortController().signal);
 

packages/core/src/tools/enter-plan-mode.ts

@@ -4,7 +4,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import fs from 'node:fs';
 import {
   BaseDeclarativeTool,
   BaseToolInvocation,
@@ -19,7 +18,6 @@ import { ENTER_PLAN_MODE_TOOL_NAME } from './tool-names.js';
 import { ApprovalMode } from '../policy/types.js';
 import { ENTER_PLAN_MODE_DEFINITION } from './definitions/coreTools.js';
 import { resolveToolDeclaration } from './definitions/resolver.js';
-import { debugLogger } from '../utils/debugLogger.js';
 
 export interface EnterPlanModeParams {
   reason?: string;
@@ -124,19 +122,6 @@ export class EnterPlanModeInvocation extends BaseToolInvocation<
 
     this.config.setApprovalMode(ApprovalMode.PLAN);
 
-    // Ensure plans directory exists so that the agent can write the plan file.
-    // In sandboxed environments, the plans directory must exist on the host
-    // before it can be bound/allowed in the sandbox.
-    const plansDir = this.config.storage.getPlansDir();
-    if (!fs.existsSync(plansDir)) {
-      try {
-        fs.mkdirSync(plansDir, { recursive: true });
-      } catch (e) {
-        // Log error but don't fail; write_file will try again later
-        debugLogger.error(`Failed to create plans directory: ${plansDir}`, e);
-      }
-    }
-
     return {
       llmContent: 'Switching to Plan mode.',
       returnDisplay: this.params.reason

packages/core/src/tools/exit-plan-mode.test.ts

@@ -44,6 +44,7 @@ describe('ExitPlanModeTool', () => {
       getTargetDir: vi.fn().mockReturnValue(tempRootDir),
       setApprovalMode: vi.fn(),
       setApprovedPlanPath: vi.fn(),
+      getPlansDir: vi.fn().mockReturnValue(mockPlansDir),
       storage: {
         getPlansDir: vi.fn().mockReturnValue(mockPlansDir),
       } as unknown as Config['storage'],

packages/core/src/tools/exit-plan-mode.ts

@@ -60,11 +60,8 @@ export class ExitPlanModeTool extends BaseDeclarativeTool<
     }
 
     const safeFilename = path.basename(params.plan_filename);
-    const plansDir = resolveToRealPath(this.config.storage.getPlansDir());
-    const resolvedPath = path.join(
-      this.config.storage.getPlansDir(),
-      safeFilename,
-    );
+    const plansDir = resolveToRealPath(this.config.getPlansDir());
+    const resolvedPath = path.join(this.config.getPlansDir(), safeFilename);
 
     const realPath = resolveToRealPath(resolvedPath);
 
@@ -120,7 +117,7 @@ export class ExitPlanModeInvocation extends BaseToolInvocation<
 
     const pathError = await validatePlanPath(
       this.params.plan_filename,
-      this.config.storage.getPlansDir(),
+      this.config.getPlansDir(),
     );
     if (pathError) {
       this.planValidationError = pathError;
@@ -170,7 +167,7 @@ export class ExitPlanModeInvocation extends BaseToolInvocation<
   }
 
   getDescription(): string {
-    return `Requesting plan approval for: ${path.join(this.config.storage.getPlansDir(), this.params.plan_filename)}`;
+    return `Requesting plan approval for: ${path.join(this.config.getPlansDir(), this.params.plan_filename)}`;
   }
 
   /**
@@ -179,7 +176,7 @@ export class ExitPlanModeInvocation extends BaseToolInvocation<
    */
   private getResolvedPlanPath(): string {
     const safeFilename = path.basename(this.params.plan_filename);
-    return path.join(this.config.storage.getPlansDir(), safeFilename);
+    return path.join(this.config.getPlansDir(), safeFilename);
   }
 
   async execute(_signal: AbortSignal): Promise<ToolResult> {

packages/core/src/tools/tool-registry.ts

@@ -617,7 +617,7 @@ export class ToolRegistry {
    */
   getFunctionDeclarations(modelId?: string): FunctionDeclaration[] {
     const isPlanMode = this.config.getApprovalMode() === ApprovalMode.PLAN;
-    const plansDir = this.config.storage.getPlansDir();
+    const plansDir = this.config.getPlansDir();
 
     const declarations: FunctionDeclaration[] = [];
     const seenNames = new Set<string>();

packages/core/src/tools/write-file.test.ts

@@ -107,6 +107,7 @@ const mockConfigInternal = {
   getDisableLLMCorrection: vi.fn(() => true),
   isPlanMode: vi.fn(() => false),
   getActiveModel: () => 'test-model',
+  getPlansDir: vi.fn().mockReturnValue('/tmp/plans'),
   storage: {
     getProjectTempDir: vi.fn().mockReturnValue('/tmp/project'),
   },

packages/core/src/tools/write-file.ts

@@ -168,10 +168,7 @@ class WriteFileToolInvocation extends BaseToolInvocation<
 
     if (this.config.isPlanMode()) {
       const safeFilename = path.basename(this.params.file_path);
-      this.resolvedPath = path.join(
-        this.config.storage.getPlansDir(),
-        safeFilename,
-      );
+      this.resolvedPath = path.join(this.config.getPlansDir(), safeFilename);
     } else {
       this.resolvedPath = path.resolve(
         this.config.getTargetDir(),