fix: add cwd to prettier hook, consistent process.exit(0), and stdout pass-through

- post-edit-format.js: add cwd based on file directory so npx resolves
  correct local prettier binary
- post-edit-typecheck.js, post-edit-format.js: replace console.log(data)
  with process.stdout.write(data) to avoid trailing newline corruption
- Add process.exit(0) to 4 hooks for consistent termination
  (check-console-log, post-edit-console-warn, post-edit-format,
  post-edit-typecheck)
- run-all.js: switch from execSync to spawnSync so stderr is visible
  on the success path (hook warnings were silently discarded)
- Add 21 tests: cwd verification, process.exit(0) checks, exact
  stdout pass-through, extension edge cases, exclusion pattern
  matching, threshold boundary values (630 → 651)

scripts/hooks/post-edit-format.js

@@ -9,6 +9,7 @@
  */
 
 const { execFileSync } = require('child_process');
+const path = require('path');
 
 const MAX_STDIN = 1024 * 1024; // 1MB limit
 let data = '';
@@ -30,6 +31,7 @@ process.stdin.on('end', () => {
         // Use npx.cmd on Windows to avoid shell: true which enables command injection
         const npxBin = process.platform === 'win32' ? 'npx.cmd' : 'npx';
         execFileSync(npxBin, ['prettier', '--write', filePath], {
+          cwd: path.dirname(path.resolve(filePath)),
           stdio: ['pipe', 'pipe', 'pipe'],
           timeout: 15000
         });
@@ -41,5 +43,6 @@ process.stdin.on('end', () => {
     // Invalid input — pass through
   }
 
-  console.log(data);
+  process.stdout.write(data);
+  process.exit(0);
 });