Make MCP server optional dependency

The fastmcp server code is now an optional dependency that can be
installed with the "mcp" extra. Core vector search functionality is
available without the MCP server dependency.

tests/test_mcp/conftest.py

@@ -0,0 +1,67 @@
+import subprocess
+import time
+
+import pytest
+from fastembed import TextEmbedding
+from qdrant_client import QdrantClient
+from qdrant_client.models import Distance, PointStruct, VectorParams
+
+
+@pytest.fixture(scope="session")
+def embedding_model():
+    return TextEmbedding()
+
+
+@pytest.fixture(scope="session")
+def qdrant_client(embedding_model: TextEmbedding):
+    client = QdrantClient(":memory:")
+
+    documents: list[str] = [
+        "Rick es el mas guapo",
+        "Los pulpos tienen tres corazones y sangre azul",
+        "Las cucarachas pueden vivir hasta una semana sin cabeza",
+        "Los koalas tienen huellas dactilares casi idénticas a las humanas",
+        "La miel nunca se echa a perder, incluso después de miles de años",
+    ]
+    embeddings = list(embedding_model.embed(documents))
+    size = len(embeddings[0])
+
+    _ = client.recreate_collection(
+        collection_name="dummy_collection",
+        vectors_config=VectorParams(distance=Distance.COSINE, size=size),
+    )
+
+    for idx, (emb, document) in enumerate(zip(embeddings, documents)):
+        _ = client.upsert(
+            collection_name="dummy_collection",
+            points=[
+                PointStruct(id=idx, vector=emb.tolist(), payload={"text": document})
+            ],
+        )
+
+    yield client
+
+
+@pytest.fixture(scope="session", autouse=True)
+def run_mcp():
+    # Start the MCP server in the background
+    process = subprocess.Popen(
+        ["uv", "run", "vector-search-mcp"],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        text=True,
+    )
+
+    # Give the server a moment to start up
+    time.sleep(2)
+
+    try:
+        yield "http://localhost:8000/sse"
+    finally:
+        # Clean up the process when tests are done
+        process.terminate()
+        try:
+            _ = process.wait(timeout=5)
+        except subprocess.TimeoutExpired:
+            process.kill()
+            _ = process.wait()