Add CLI header integration tests and update test scripts

- Introduced integration tests for header functionality in a new script `cli-header-tests.js`.
- Updated the `package.json` to include the new test script and modified the existing test command to run all tests.
- Adjusted the main CLI exit behavior to ensure proper termination in CI environments.
- Added `.claude/settings.local.json` to `.gitignore` to prevent local settings from being tracked.

cli/src/index.ts

@@ -352,8 +352,8 @@ async function main(): Promise<void> {
     const args = parseArgs();
     await callMethod(args);
 
-    // Let Node.js naturally exit instead of force-exiting
-    // process.exit(0) was causing stdout truncation
+    // Explicitly exit to ensure process terminates in CI
+    process.exit(0);
   } catch (error) {
     handleError(error);
   }