fix(coding-agent): prevented asynchronous write races in plan reviews

- Ensures in-memory overlay edits are durably written to the plan file before proceeding with approval.
- Avoids asynchronous write races by awaiting the final plan file serialization.
- Aligns synthetic approved-plan prompts with reference-only expectations.

packages/coding-agent/src/modes/interactive-mode.ts

@@ -3138,10 +3138,13 @@ export class InteractiveMode implements InteractiveModeContext {
 
 		if (choice === "Approve and execute" || choice === "Approve and compact context" || choice === keepContextLabel) {
 			try {
-				// Prefer in-overlay edits (already in memory) over a disk re-read; the
-				// `onPlanEdited` write is fire-and-forget, so reading the file here could
-				// race ahead of it.
+				// Prefer in-overlay edits (already in memory) over a disk re-read. The
+				// overlay mirrors edits as they happen, and approval awaits one final
+				// write so the durable plan file and synthetic prompt carry the same text.
 				const latestPlanContent = editedContent ?? (await this.#readPlanFile(planFilePath));
+				if (editedContent !== undefined) {
+					await Bun.write(this.#resolvePlanFilePath(planFilePath), editedContent);
+				}
 				if (!latestPlanContent) {
 					this.showError(`Plan file not found at ${planFilePath}`);
 					return;

packages/coding-agent/src/plan-mode/approved-plan-prompt.test.ts

@@ -10,7 +10,7 @@ const PLAN_FILE_PATH = "local://durable-plan.md";
 const PLAN_SENTINEL = "SENTINEL_HEADROOM_COMPRESSED_PLAN_CONTENT";
 
 describe("approved plan execution prompts", () => {
-	it("loads the approved plan from the durable local file instead of embedding content", () => {
+	it("requires reading the durable plan file without inlining plan content", () => {
 		const approved = prompt.render(planModeApprovedPrompt, {
 			planContent: PLAN_SENTINEL,
 			planFilePath: PLAN_FILE_PATH,
@@ -26,6 +26,8 @@ describe("approved plan execution prompts", () => {
 
 		for (const rendered of [approved, reference, compact]) {
 			expect(rendered).toContain(PLAN_FILE_PATH);
+		}
+		for (const rendered of [approved, reference, compact]) {
 			expect(rendered).not.toContain(PLAN_SENTINEL);
 		}
 		expect(approved).toContain("MUST read `local://durable-plan.md`");

packages/coding-agent/test/interactive-mode-plan-review.test.ts

@@ -380,7 +380,14 @@ describe("InteractiveMode plan review rendering", () => {
 			return "Approve and execute";
 		});
 		vi.spyOn(mode, "handleClearCommand").mockResolvedValue();
-		const promptSpy = vi.spyOn(session, "prompt").mockResolvedValue(undefined as never);
+		const promptSpy = vi.spyOn(session, "prompt").mockImplementation(async promptText => {
+			if (typeof promptText === "string" && promptText.startsWith("Plan approved.")) {
+				const persisted = await Bun.file(resolvedPlanPath).text();
+				expect(persisted).toContain("edited body");
+				expect(persisted).not.toContain("original body");
+			}
+			return undefined as never;
+		});
 
 		await mode.handlePlanApproval({
 			planFilePath,
@@ -388,11 +395,11 @@ describe("InteractiveMode plan review rendering", () => {
 			title: "PLAN",
 		});
 
-		// The synthetic plan-approved prompt carries the in-overlay edit, not the
-		// stale on-disk content (preferring editedContent avoids the write race).
+		// The plan-approved prompt stays reference-only; approval must instead
+		// await the durable file mirror before dispatch so read sees the edit.
 		const call = promptSpy.mock.calls.find(isPlanApprovedCall);
 		expect(call).toBeDefined();
-		expect(call?.[0] as string).toContain("edited body");
+		expect(call?.[0] as string).not.toContain("edited body");
 		expect(call?.[0] as string).not.toContain("original body");
 		// onPlanEdited mirrored the edit to the plan file.
 		expect(await Bun.file(resolvedPlanPath).text()).toContain("edited body");

packages/coding-agent/test/task/worktree.test.ts

@@ -14,8 +14,8 @@ import {
 	mergeTaskBranches,
 	parseIsolationMode,
 } from "@oh-my-pi/pi-coding-agent/task/worktree";
-import * as jj from "@oh-my-pi/pi-coding-agent/utils/jj";
 import * as git from "@oh-my-pi/pi-coding-agent/utils/git";
+import * as jj from "@oh-my-pi/pi-coding-agent/utils/jj";
 import * as natives from "@oh-my-pi/pi-natives";
 import { removeWithRetries, setWorktreesDir } from "@oh-my-pi/pi-utils";
 

packages/tui/src/tui.ts

@@ -3611,8 +3611,14 @@ export class TUI extends Container {
 			repaintVirtualScrollInPlace: boolean;
 		},
 	): void {
-		const { chunkTo, windowTop, prevWindowTop, prevHardwareCursorRow, forceWindowRewrite, repaintVirtualScrollInPlace } =
-			options;
+		const {
+			chunkTo,
+			windowTop,
+			prevWindowTop,
+			prevHardwareCursorRow,
+			forceWindowRewrite,
+			repaintVirtualScrollInPlace,
+		} = options;
 		const chunkFrom = this.#committedRows;
 		const chunkLength = chunkTo - chunkFrom;
 		const scroll = windowTop - prevWindowTop;