feat: API key routes, search endpoint, conversation type wiring

- GET/POST/DELETE /api/api-keys blueprint registered
- GET /api/search?q=&content_type=&limit= semantic search endpoint
- create_conversation gains conversation_type param (default "chat")
- cleanup_old_conversations excludes mcp type from retention sweep
- POST /api/chat/conversations accepts conversation_type body field

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

src/fabledassistant/routes/api_keys.py

@@ -0,0 +1,42 @@
+from quart import Blueprint, jsonify, request
+
+from fabledassistant.auth import login_required, get_current_user_id
+from fabledassistant.services.api_keys import create_api_key, list_api_keys, revoke_api_key
+
+api_keys_bp = Blueprint("api_keys", __name__, url_prefix="/api/api-keys")
+
+
+@api_keys_bp.route("", methods=["GET"])
+@login_required
+async def list_keys_route():
+    uid = get_current_user_id()
+    keys = await list_api_keys(uid)
+    return jsonify({"api_keys": keys})
+
+
+@api_keys_bp.route("", methods=["POST"])
+@login_required
+async def create_key_route():
+    uid = get_current_user_id()
+    data = await request.get_json(force=True, silent=True) or {}
+    name = (data.get("name") or "").strip()
+    scope = (data.get("scope") or "").strip()
+
+    if not name:
+        return jsonify({"error": "name is required"}), 400
+    if scope not in ("read", "write"):
+        return jsonify({"error": "scope must be 'read' or 'write'"}), 400
+
+    full_key, key_dict = await create_api_key(uid, name=name, scope=scope)
+    # Return the full key ONCE — it is never retrievable again
+    return jsonify({"key": full_key, "api_key": key_dict}), 201
+
+
+@api_keys_bp.route("/<int:key_id>", methods=["DELETE"])
+@login_required
+async def revoke_key_route(key_id: int):
+    uid = get_current_user_id()
+    deleted = await revoke_api_key(uid, key_id)
+    if not deleted:
+        return jsonify({"error": "API key not found"}), 404
+    return "", 204