🔧 Fix CI file deletion issue by using workspace temp directory

ROOT CAUSE DISCOVERED: GitHub Actions immediately deletes files created in RUNNER_TEMP
- File writes succeed but files disappear immediately after creation
- writeFileSync succeeds but realpathSync fails with ENOENT
- Switch to workspace-based temp directory: process.cwd()/test-tmp/
- Add test-tmp/ to .gitignore

This should finally fix the 8 CI test failures.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: secondcircle

.gitignore

@@ -57,6 +57,7 @@ Thumbs.db
 # Temporary files
 tmp/
 temp/
+test-tmp/
 
 # MCP specific
 mcp/*/storage.json

src/file-editor-rollback.test.ts

@@ -4,8 +4,8 @@ import { join } from 'node:path';
 import { applyWorkspaceEdit } from './file-editor.js';
 import { pathToUri } from './utils.js';
 
-const TEST_DIR = process.env.RUNNER_TEMP
-  ? `${process.env.RUNNER_TEMP}/file-editor-rollback-test`
+const TEST_DIR = process.env.CI
+  ? `${process.cwd()}/test-tmp/file-editor-rollback-test`
   : '/tmp/file-editor-rollback-test';
 
 describe('file-editor rollback without backups', () => {

src/file-editor-symlink.test.ts

@@ -76,8 +76,8 @@ async function robustReadThroughSymlink(link: string): Promise<string> {
   return readFileSync(link, 'utf-8');
 }
 
-const TEST_DIR = process.env.RUNNER_TEMP
-  ? `${process.env.RUNNER_TEMP}/file-editor-symlink-test`
+const TEST_DIR = process.env.CI
+  ? `${process.cwd()}/test-tmp/file-editor-symlink-test`
   : '/tmp/file-editor-symlink-test';
 
 describe.skipIf(!canCreateSymlinks())('file-editor symlink handling', () => {