fix: migrate coding-agent tests from fs.rm to removeWithRetries

Migrate 203 test files (356 call sites) from fs.rm/fs.rmSync to
removeWithRetries/removeSyncWithRetries to reduce EBUSY test failures
on Windows. removeWithRetries is now exported from @oh-my-pi/pi-utils.

The migration uses a regex-based approach that:
- Replaces fs.rm(path, { recursive, force }) → removeWithRetries(path)
- Replaces fs.rmSync(path, { recursive, force }) → removeSyncWithRetries(path)
- Replaces fs.rm(path) → removeWithRetries(path) (no options)
- Skips fs.rm/fs.rmSync inside template literals (bun --eval scripts)
- Adds imports to existing @oh-my-pi/pi-utils import or creates new one
- Removes unused fs imports where fs.rm was the only fs usage (4 files)

packages/coding-agent/test/cli/ttsr-cli.test.ts

@@ -10,7 +10,7 @@ import {
 	type TtsrTestArgs,
 } from "@oh-my-pi/pi-coding-agent/cli/ttsr-cli";
 import { resetSettingsForTest } from "@oh-my-pi/pi-coding-agent/config/settings";
-import { getProjectAgentDir, getProjectDir, setProjectDir } from "@oh-my-pi/pi-utils";
+import { getProjectAgentDir, getProjectDir, removeSyncWithRetries, setProjectDir } from "@oh-my-pi/pi-utils";
 
 let testTmpDir: string;
 
@@ -20,7 +20,7 @@ beforeAll(() => {
 
 afterAll(() => {
 	if (testTmpDir && fs.existsSync(testTmpDir)) {
-		fs.rmSync(testTmpDir, { force: true, recursive: true });
+		removeSyncWithRetries(testTmpDir);
 	}
 });
 
@@ -92,7 +92,7 @@ async function writeTempSnippet(content: string, ext: string): Promise<string> {
 function cleanupTmp(): void {
 	if (!testTmpDir || !fs.existsSync(testTmpDir)) return;
 	for (const entry of fs.readdirSync(testTmpDir)) {
-		fs.rmSync(path.join(testTmpDir, entry), { force: true, recursive: true });
+		removeSyncWithRetries(path.join(testTmpDir, entry));
 	}
 }