feat: KIS (Korea Investment) market data collector service

- KIS API integration for stock prices and market data
- GET /stocks endpoint with search, filter, pagination
- GET /stocks/{code} endpoint with prices and valuation
- REST API with health, streams, and trigger endpoints
- Redis Streams for async job processing
- Docker support with multi-stage build

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

Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+COPY stock-common/ /tmp/stock-common/
+RUN pip install --no-cache-dir /tmp/stock-common/ && rm -rf /tmp/stock-common/
+
+COPY stock-kis-collector/ .
+RUN pip install --no-cache-dir .
+
+CMD ["python", "-m", "stock_kis_collector.worker"]