refactor: split openai/ into ollama/, openwebui/, searxng/

Move services out of the monolithic openai/docker-compose.yml:
- ollama/ — ollama GPU + CPU inference servers
- openwebui/ — open-webui chat UI (uses env var for ANTHROPIC_API_KEY)
- searxng/ — SearXNG container + searxng-mcp MCP server (port 3102)

openai/ now contains only: litellm, langfuse, qdrant, faster-whisper,
silero-tts, pipecat.

searxng-mcp exposes a single searxng_search tool via MCP HTTP on :3102.
Registered in ~/.claude.json as the "searxng" MCP server.

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

searxng/docker-compose.yml

@@ -0,0 +1,19 @@
+services:
+  searxng:
+    image: docker.io/searxng/searxng:latest
+    container_name: searxng
+    volumes:
+      - /mnt/ssd/ai/searxng/config/:/etc/searxng/
+      - /mnt/ssd/ai/searxng/data/:/var/cache/searxng/
+    restart: always
+    ports:
+      - "11437:8080"
+
+  searxng-mcp:
+    build: ./mcp
+    container_name: searxng-mcp
+    network_mode: host
+    restart: unless-stopped
+    environment:
+      - PORT=3102
+      - SEARXNG_URL=http://localhost:11437