feat: add analysis pages and raster risk map

Ship a new app version with broader analytics, restructured
dashboards, and a server-rendered risk map.

Frontend:
- Add Overview, Demographic, Disease, and Environmental Health
  analysis pages
- Add AnomalyMarkers, CalendarHeatmap, and MetricHeatmapTable
  components
- Rebuild Alerts map onto server-rendered raster risk tiles;
  expand Monitoring, Trend, and District Comparison views
- Extend API client, stores, and TypeScript types

Backend:
- Add environment router (pollutants, lag correlations)
- Add risk_raster util serving XYZ 100m risk tiles
- Expand cases endpoints (demographics, seasonality, diagnoses)
  and insights; harden auth and file-based loaders

Data & tooling:
- Add processed outpatient/inpatient/combined case parquet (LFS)
- Add nested CLAUDE.md guides, pyrightconfig, and test updates

backend/routers/alerts.py

@@ -5,6 +5,8 @@ Generates alerts from high-risk grids in GeoJSON files
 from fastapi import APIRouter, HTTPException, Query
 from datetime import datetime
 from typing import List
+from functools import lru_cache
+import asyncio
 import json
 
 from config import DATA_DIR, ALERT_P1_RISK, ALERT_P2_RISK, WUHAN_BOUNDS, LAT_STEP, LON_STEP, MAX_ALERTS
@@ -32,8 +34,13 @@ def grid_id_to_center(grid_id: str) -> tuple[float, float]:
     return lat, lon
 
 
-def generate_alerts_for_date(date: str) -> List[Alert]:
-    """Generate alerts for high-risk grids on a specific date.
+@lru_cache(maxsize=8)
+def _generate_alerts_cached(date: str) -> List[Alert]:
+    """Heavy synchronous worker: parse the ~45MB GeoJSON and build alerts.
+
+    Cached by date so the file is parsed once per date. This runs blocking
+    json.load + per-feature loops, so callers must invoke it off the event
+    loop (see generate_alerts_for_date).
 
     Phase 1: iterate features, aggregate max risk per 100m grid cell.
     Phase 2: build Alert objects from aggregated grid cells.
@@ -111,6 +118,16 @@ def generate_alerts_for_date(date: str) -> List[Alert]:
     return alerts[:MAX_ALERTS]
 
 
+async def generate_alerts_for_date(date: str) -> List[Alert]:
+    """Async accessor: run the cached heavy parser in a thread pool.
+
+    Offloading the blocking json.load + per-feature aggregation keeps the
+    event loop free. The lru_cache lives on the worker, so warm dates return
+    near-instantly without re-parsing.
+    """
+    return await asyncio.to_thread(_generate_alerts_cached, date)
+
+
 @router.get("", response_model=AlertResponse)
 async def list_alerts(date: str | None = None, priority: str | None = None, min_risk: float | None = None):
     if date is not None and not validate_date_format(date):
@@ -118,7 +135,7 @@ async def list_alerts(date: str | None = None, priority: str | None = None, min_
     if date is None:
         date = get_latest_date()
 
-    alerts = generate_alerts_for_date(date)
+    alerts = await generate_alerts_for_date(date)
 
     if priority:
         alerts = [a for a in alerts if a.priority == priority]
@@ -140,7 +157,7 @@ async def get_alert(alert_id: str, date: str | None = None):
     if date is None:
         date = get_latest_date()
 
-    alerts = generate_alerts_for_date(date)
+    alerts = await generate_alerts_for_date(date)
 
     for alert in alerts:
         if alert.alert_id == alert_id:
@@ -156,7 +173,7 @@ async def get_p1_alerts(date: str | None = None):
     if date is None:
         date = get_latest_date()
 
-    alerts = generate_alerts_for_date(date)
+    alerts = await generate_alerts_for_date(date)
     p1_alerts = [a for a in alerts if a.priority == "P1"]
 
     return AlertResponse(
@@ -173,7 +190,7 @@ async def get_p2_alerts(date: str | None = None):
     if date is None:
         date = get_latest_date()
 
-    alerts = generate_alerts_for_date(date)
+    alerts = await generate_alerts_for_date(date)
     p2_alerts = [a for a in alerts if a.priority == "P2"]
 
     return AlertResponse(
@@ -190,7 +207,7 @@ async def get_grid_alerts(grid_id: str, date: str | None = None):
     if date is None:
         date = get_latest_date()
 
-    alerts = generate_alerts_for_date(date)
+    alerts = await generate_alerts_for_date(date)
     grid_alerts = [a for a in alerts if a.grid_id == grid_id]
 
     return AlertResponse(