fix: improve MCP service startup reliability

- Clarify OPENAI_API_BASE can be left empty for default endpoint
- Increase initial wait time from 3s to 5s
- Add health checking for all MCP services (ports 8000-8003)
- Retry up to 10 times with 1s intervals
- Install netcat for port checking
- Display warnings if services aren't ready

Helps diagnose and prevent MCP client initialization errors.

Dockerfile

@@ -3,7 +3,12 @@ FROM python:3.10-slim AS base
 
 WORKDIR /app
 
-# Install dependencies
+# Install system dependencies
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends netcat-openbsd && \
+    rm -rf /var/lib/apt/lists/*
+
+# Install Python dependencies
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt