modify: cleanup project structure and docs

ui_sections/overview.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+import json
+import pandas as pd
+import plotly.graph_objects as go
+import streamlit as st
+
+def render_overview(base: pd.DataFrame, region_sel: str, start_dt: pd.Timestamp, end_dt: pd.Timestamp,
+                    strat_filter: list[str]):
+    fig_line = go.Figure()
+    fig_line.add_trace(go.Scatter(x=base.index, y=base['accident_count'], name='事故数', mode='lines'))
+    fig_line.update_layout(title="事故数（过滤后）", xaxis_title="Date", yaxis_title="Count")
+    st.plotly_chart(fig_line, use_container_width=True)
+
+    html = fig_line.to_html(full_html=True, include_plotlyjs='cdn')
+    st.download_button("下载图表 HTML", data=html.encode('utf-8'),
+                       file_name="overview_series.html", mime="text/html")
+
+    st.dataframe(base, use_container_width=True)
+    csv_bytes = base.to_csv(index=True).encode('utf-8-sig')
+    st.download_button("下载当前视图 CSV", data=csv_bytes, file_name="filtered_view.csv", mime="text/csv")
+
+    meta = {
+        "region": region_sel,
+        "date_range": [str(start_dt.date()), str(end_dt.date())],
+        "strategy_filter": strat_filter,
+        "rows": int(len(base)),
+        "min_date": str(base.index.min().date()) if len(base) else None,
+        "max_date": str(base.index.max().date()) if len(base) else None,
+    }
+    st.download_button("下载运行参数 JSON", data=json.dumps(meta, ensure_ascii=False, indent=2).encode('utf-8'),
+                       file_name="run_metadata.json", mime="application/json")
+