Initial release: MeshCore Stats monitoring system

A Python-based monitoring system for MeshCore LoRa mesh networks.
Collects metrics from companion and repeater nodes, stores them in
a SQLite database, and generates a static website with interactive
SVG charts and statistics.

Features:
- Data collection from local companion and remote repeater nodes
- SQLite database with EAV schema for flexible metric storage
- Interactive SVG chart generation with matplotlib
- Static HTML site with day/week/month/year views
- Monthly and yearly statistics reports (HTML, TXT, JSON)
- Light and dark theme support
- Circuit breaker for unreliable LoRa connections
- Battery percentage calculation from 18650 discharge curves
- Automated releases via release-please

Live demo: https://meshcore.jorijn.com

scripts/render_charts.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""
+Phase 2: Render charts from SQLite database.
+
+Generates SVG charts for day/week/month/year for both companion and repeater
+using matplotlib, reading directly from the SQLite metrics database.
+"""
+
+import sys
+from pathlib import Path
+
+# Add src to path for imports
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from meshmon.db import init_db, get_metric_count
+from meshmon import log
+from meshmon.charts import render_all_charts, save_chart_stats
+
+
+def main():
+    """Render all charts and save statistics."""
+    # Ensure database is initialized
+    init_db()
+
+    log.info("Rendering charts from database...")
+
+    # Check if data exists before rendering
+    companion_count = get_metric_count("companion")
+    repeater_count = get_metric_count("repeater")
+
+    # Companion charts
+    if companion_count > 0:
+        charts, stats = render_all_charts("companion")
+        save_chart_stats("companion", stats)
+        log.info(f"Rendered {len(charts)} companion charts ({companion_count} data points)")
+    else:
+        log.warn("No companion metrics in database")
+
+    # Repeater charts
+    if repeater_count > 0:
+        charts, stats = render_all_charts("repeater")
+        save_chart_stats("repeater", stats)
+        log.info(f"Rendered {len(charts)} repeater charts ({repeater_count} data points)")
+    else:
+        log.warn("No repeater metrics in database")
+
+    log.info("Chart rendering complete")
+
+
+if __name__ == "__main__":
+    main()