feat(settings): model management UI — pull, delete, VRAM status

Backend:
- Enrich GET /api/chat/models to also hit /api/ps and return loaded:bool
  and modified_at alongside name/size, using parallel gather

Frontend (Settings → General):
- Model list: each row shows name (monospace), size (GB/MB), 'in VRAM' badge
  if currently loaded, 'default' badge if it's the configured default
- Delete button per row; disabled while deletion in progress
- Pull form: text input (Enter submits) + Pull button
- Suggestion chips for qwen3:7b/14b/4b, llama3.1:8b, nomic-embed-text;
  disabled if already installed
- Progress display during pull: status text + determinate bar when
  Ollama reports total/completed, indeterminate animation otherwise
- Refresh button reloads the list; list auto-refreshes after pull/delete
- Link to ollama.com/library for model discovery

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/routes/chat.py

@@ -405,14 +405,29 @@ async def chat_status_route():
 async def list_models_route():
     try:
         async with httpx.AsyncClient(timeout=10.0) as client:
-            resp = await client.get(f"{Config.OLLAMA_URL}/api/tags")
-            resp.raise_for_status()
-            data = resp.json()
-            models = [
-                {"name": m["name"], "size": m.get("size", 0)}
-                for m in data.get("models", [])
-            ]
-            return jsonify({"models": models})
+            tags_task = asyncio.create_task(client.get(f"{Config.OLLAMA_URL}/api/tags"))
+            ps_task = asyncio.create_task(client.get(f"{Config.OLLAMA_URL}/api/ps"))
+            tags_resp, ps_resp = await asyncio.gather(tags_task, ps_task, return_exceptions=True)
+
+        loaded_names: set[str] = set()
+        if not isinstance(ps_resp, Exception):
+            try:
+                ps_resp.raise_for_status()
+                loaded_names = {m["name"] for m in ps_resp.json().get("models", [])}
+            except Exception:
+                pass
+
+        models = []
+        if not isinstance(tags_resp, Exception):
+            tags_resp.raise_for_status()
+            for m in tags_resp.json().get("models", []):
+                models.append({
+                    "name": m["name"],
+                    "size": m.get("size", 0),
+                    "modified_at": m.get("modified_at", ""),
+                    "loaded": m["name"] in loaded_names,
+                })
+        return jsonify({"models": models})
     except Exception as e:
         logger.warning("Failed to list Ollama models: %s", e)
         return jsonify({"models": [], "error": str(e)}), 200