feat: GeoScene frontend POC + Docker deploy for remote host

Migrate maps to @geoscene/core, polish monitoring/alerts UX, fix timeline
basemap flicker and district alert regions, and ship compose/nginx Docker
deploy assets with CBPOA_ROOT data mounts.

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/backend/Dockerfile

@@ -1,32 +1,26 @@
 FROM python:3.11-slim
 
-# Install system dependencies
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    libpq-dev \
+    libpq-dev curl \
     && rm -rf /var/lib/apt/lists/*
 
-# Create non-root user
 RUN groupadd --gid 1000 appgroup && \
     useradd --uid 1000 --gid appgroup --shell /bin/bash --create-home appuser
 
-WORKDIR /home/appuser
+WORKDIR /app
 
-# Copy requirements and install dependencies
 COPY --chown=appuser:appgroup requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt \
+    -i https://pypi.tuna.tsinghua.edu.cn/simple
 
-# Copy backend code
 COPY --chown=appuser:appgroup . .
 
-# Switch to non-root user
 USER appuser
 
-# Expose port
+ENV CBPOA_ROOT=/data
 EXPOSE 8000
 
-# Health check
-HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+HEALTHCHECK --interval=30s --timeout=10s --start-period=20s --retries=3 \
     CMD curl -f http://localhost:8000/docs || exit 1
 
-# Run uvicorn
 CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]