feat(plan): support replace tool in plan mode to edit plans (#18379)

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

@@ -130,6 +130,7 @@ You are operating in **Plan Mode** - a structured planning workflow for designin
 The following read-only tools are available in Plan Mode:
 
 - \`write_file\` - Save plans to the plans directory (see Plan Storage below)
+- \`replace\` - Update plans in the plans directory
 
 ## Plan Storage
 - Save your plans as Markdown (.md) files ONLY within: \`/tmp/project-temp/plans/\`

packages/core/src/policy/config.test.ts

@@ -327,7 +327,10 @@ describe('createPolicyEngineConfig', () => {
       ApprovalMode.AUTO_EDIT,
     );
     const rule = config.rules?.find(
-      (r) => r.toolName === 'replace' && r.decision === PolicyDecision.ALLOW,
+      (r) =>
+        r.toolName === 'replace' &&
+        r.decision === PolicyDecision.ALLOW &&
+        r.modes?.includes(ApprovalMode.AUTO_EDIT),
     );
     expect(rule).toBeDefined();
     // Priority 15 in default tier → 1.015

packages/core/src/policy/policies/plan.toml

@@ -77,9 +77,9 @@ decision = "ask_user"
 priority = 50
 modes = ["plan"]
 
-# Allow write_file for .md files in plans directory
+# Allow write_file and replace for .md files in plans directory
 [[rule]]
-toolName = "write_file"
+toolName = ["write_file", "replace"]
 decision = "allow"
 priority = 50
 modes = ["plan"]

packages/core/src/prompts/snippets.ts

@@ -305,6 +305,7 @@ You are operating in **Plan Mode** - a structured planning workflow for designin
 The following read-only tools are available in Plan Mode:
 ${options.planModeToolsList}
 - \`${WRITE_FILE_TOOL_NAME}\` - Save plans to the plans directory (see Plan Storage below)
+- \`${EDIT_TOOL_NAME}\` - Update plans in the plans directory
 
 ## Plan Storage
 - Save your plans as Markdown (.md) files ONLY within: \`${options.plansDir}/\`