Prefer AGENTS.md over CLAUDE.md for project instructions (#439)

* Prefer AGENTS.md over CLAUDE.md for project instructions

* fix: preserve CLAUDE.md fallback behavior

* fix: isolate onboarding tests and preserve legacy init

* fix: restore full fsOperations exports in test mock and align compact cwd

* Fix onboarding test isolation and init migration guidance

* Tighten init prompt coverage and onboarding copy

* Handle nested project instruction paths consistently

* Fix NEW_INIT feature gate for Bun build

---------

Co-authored-by: 赵小落 <zhaoxiaoluo@zhaoxiaoluodeMac-mini.local>
Co-authored-by: zhaomo01 <zhaomo01@baidu.com>

src/tools/FileWriteTool/FileWriteTool.ts

@@ -336,8 +336,11 @@ export const FileWriteTool = buildTool({
       limit: undefined,
     })
 
-    // Log when writing to CLAUDE.md
-    if (fullFilePath.endsWith(`${sep}CLAUDE.md`)) {
+    // Log when writing to the root project instruction file
+    if (
+      fullFilePath.endsWith(`${sep}AGENTS.md`) ||
+      fullFilePath.endsWith(`${sep}CLAUDE.md`)
+    ) {
       logEvent('tengu_write_claudemd', {})
     }