KI-Chat: interaktiver Bewerbungs-Assistent (Ollama-Streaming)

Eigenes Chat-Interface mit SSE-Streaming gegen das hinterlegte Ollama-Modell,
gegroundet in den Bewerbungs-/E-Mail-/Termindaten des Nutzers.

- lib/chat.js: streamChat (Ollama stream:true, NDJSON-Token) + buildContextPrompt
- chat_threads/chat_messages Tabellen (CASCADE, Index)
- Routen: GET /chat, Thread-CRUD, POST /messages (SSE, AbortController)
- views/chat.ejs + public/js/chat.js + Floating-Button im Footer
- hasApiKey-Gating (503 ohne OLLAMA_API_KEY)

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

views/partials/footer.ejs

@@ -6,3 +6,13 @@
         </p>
     </div>
 </footer>
+
+<!-- Floating button: open the KI chat assistant -->
+<a href="/chat"
+   class="fixed bottom-5 right-5 z-40 flex items-center gap-2 rounded-full bg-blue-600 hover:bg-blue-700 text-white shadow-lg px-4 py-3 text-sm font-medium transition-colors"
+   title="KI-Bewerbungs-Assistent öffnen">
+    <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 10h8M8 14h5m4 7a8 8 0 100-16 8 8 0 000 16z"></path>
+    </svg>
+    <span class="hidden sm:inline">KI-Chat</span>
+</a>