feat: create PARSER service skeleton with FastAPI

- Create parser-service/ with full structure
- Add FastAPI app with endpoints (/parse, /parse_qa, /parse_markdown, /parse_chunks)
- Add Pydantic schemas (ParsedDocument, ParsedBlock, ParsedChunk, etc.)
- Add runtime module with model_loader and inference (with dummy parser)
- Add configuration, Dockerfile, requirements.txt
- Update TODO-PARSER-RAG.md with completed tasks
- Ready for dots.ocr model integration

services/parser-service/Dockerfile

@@ -0,0 +1,27 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y \
+    poppler-utils \
+    libgl1-mesa-glx \
+    libglib2.0-0 \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy requirements and install dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY . .
+
+# Create temp directory
+RUN mkdir -p /tmp/parser
+
+# Expose port
+EXPOSE 9400
+
+# Run application
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "9400"]
+