v4 Schritt 3: 'Verbinden'-Tab (Orchestrierung)

- routers/integration.py: GET /api/integration/test ruft Engine /v1/models -> ok + Modell-Liste.
- connect.js: Verbindungstest-Button, Bild/Vision-Flow (erkennt Vision-Modell, sonst Cookbook-Hinweis,
  OpenAI-Vision-Snippet), Tool-Configs (OpenCode/Cline/Cursor/OpenWebUI) mit Copy.
- Nav-Eintrag 'Verbinden' + View + main.js Registrierung.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

static/index.html

@@ -19,6 +19,7 @@
       <a class="nav-item" data-view="activity"><span class="ni-ic" data-ic="pulse"></span><span class="ni-tx">Aktivität</span></a>
       <a class="nav-item" data-view="server"><span class="ni-ic" data-ic="server"></span><span class="ni-tx">Server</span></a>
       <a class="nav-item" data-view="cookbook"><span class="ni-ic" data-ic="book"></span><span class="ni-tx">Cookbook</span></a>
+      <a class="nav-item" data-view="connect"><span class="ni-ic" data-ic="swap"></span><span class="ni-tx">Verbinden</span></a>
       <a class="nav-item" data-view="guides"><span class="ni-ic" data-ic="help"></span><span class="ni-tx">Guides</span></a>
     </nav>
     <div class="side-foot">
@@ -72,6 +73,10 @@
         <!-- Wird von cookbook.js gerendert -->
       </section>
 
+      <section class="view" data-view="connect" hidden>
+        <!-- Wird von connect.js gerendert -->
+      </section>
+
       <section class="view" data-view="guides" hidden>
         <!-- Wird von guides.js gerendert -->
       </section>