test: give daemon-control tests a unique port (3212 was already taken)

test/sse-subscription-filter.test.ts already binds 3212; sequential test
execution hid the clash. Moves the probeServer fixture to 3216 (3217 for
the nothing-listening case) per the unique-port convention.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/daemon-control.test.ts

@@ -16,7 +16,7 @@ import {
   probeServer,
 } from '../src/daemon-control.js';
 
-const PORT = 3212;
+const PORT = 3216;
 
 describe('buildWebArgs', () => {
   it('always passes host and port through explicitly', () => {