fix: switch MCP server to stdio transport for llmx compatibility

- Add wrapper script run-crawl4ai-mcp.sh for stdio transport
- Update config.toml to use stdio instead of SSE
- llmx uses Streamable HTTP transport which is incompatible with SSE
- DB and REST still run via docker compose, MCP runs on-demand

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

run-crawl4ai-mcp.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Wrapper script to run crawl4ai-rag MCP server with environment variables
+set -a
+source "$(dirname "$0")/.env"
+set +a
+
+exec docker run -i --rm \
+  --network=llmx_default \
+  -e TRANSPORT=stdio \
+  -e SUPABASE_URL=http://crawl4ai-rest:3000 \
+  -e SUPABASE_SERVICE_KEY="$SUPABASE_SERVICE_KEY" \
+  -e OPENAI_API_KEY="$LITELLM_API_KEY" \
+  -e EMBEDDING_API_BASE=https://llm.ai.pivoine.art/v1 \
+  -e EMBEDDING_MODEL=bge-large-en-v1.5 \
+  -e EMBEDDING_DIMENSION=1024 \
+  llmx-crawl4ai-rag