Require the hook-event secret unconditionally, not only under a managed tunnel

COD-54 gated the /api/hook-event + /api/status-telemetry localhost bypass
behind the shared X-Codeman-Hook-Secret only WHILE a managed tunnel was
running, keeping a plain localhost bypass otherwise. But Codeman can't detect
a user's OWN loopback reverse proxy (their own `cloudflared --url`,
`tailscale serve`, nginx -> 127.0.0.1), which proxies internet traffic into
the loopback origin with req.ip === 127.0.0.1 — so that setup kept the unsafe
plain bypass.

Require the secret on the loopback bypass unconditionally. Managed-session
hooks already always present it (X-Codeman-Hook-Secret from
$CODEMAN_HOOK_SECRET_FILE, generated for every instance), so the legitimate
hook channel is unaffected; only the previously-unguarded own-proxy path is
now rejected. Drops the now-unused getTunnelRunning param from
registerAuthMiddleware.

Tests: cod54-hook-event-auth (tunnel-down now also requires the secret, plus
a good-secret positive case); auth-security (hook tests present the secret to
reach schema validation).

test/auth-security.test.ts

@@ -14,6 +14,7 @@ import { describe, it, expect, beforeAll, afterAll, beforeEach, afterEach, vi }
 import { WebServer } from '../src/web/server.js';
 import { TmuxManager } from '../src/tmux-manager.js';
 import { SettingsUpdateSchema } from '../src/web/schemas.js';
+import { getHookSecret, HOOK_SECRET_HEADER } from '../src/config/hook-secret.js';
 
 const AUTH_PORT = 3160;
 const NOAUTH_PORT = 3161;
@@ -250,28 +251,28 @@ describe('Auth Security', () => {
   });
 
   describe('Hook Event Endpoint', () => {
-    it('should allow hook events from localhost without auth', async () => {
+    it('should allow hook events from localhost with the hook secret (no Basic auth)', async () => {
       const res = await fetch(`${baseUrl}/api/hook-event`, {
         method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
+        headers: { 'Content-Type': 'application/json', [HOOK_SECRET_HEADER]: getHookSecret() },
         body: JSON.stringify({
           event: 'stop',
           sessionId: 'nonexistent-session',
           data: {},
         }),
       });
-      // Should pass auth (localhost bypass) but may 404 on session — that's fine
-      // The key assertion is it does NOT return 401
+      // Should pass auth (localhost bypass + hook secret) but may 404 on session — that's fine.
+      // The key assertion is it does NOT return 401 (COD-91: secret required even with no tunnel).
       expect(res.status).not.toBe(401);
     });
 
     it('should reject hook events with invalid schema', async () => {
       const res = await fetch(`${baseUrl}/api/hook-event`, {
         method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
+        headers: { 'Content-Type': 'application/json', [HOOK_SECRET_HEADER]: getHookSecret() },
         body: JSON.stringify({ invalid: 'data' }),
       });
-      // Schema validation should catch this
+      // Past the auth gate (valid secret) → schema validation should catch this (not a 401).
       expect(res.status).not.toBe(401); // Not an auth error
     });
   });