Fix: Use Kerykeion 4.x API for SVG chart generation

🐛 Fixes:
- Use KerykeionChartSVG instead of ChartDrawer (4.x vs 5.x)
- Use AstrologicalSubject instead of AstrologicalSubjectFactory
- Compatible with kerykeion==4.18.1 installed in requirements.txt

✨ Features:
- Professional SVG chart with aspects
- POST /api/generate-chart-svg endpoint
- Returns SVG directly for frontend embedding

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app.py

@@ -7,9 +7,7 @@ from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import Response
 from pydantic import BaseModel
-from kerykeion import AstrologicalSubject, AstrologicalSubjectFactory
-from kerykeion.chart_data_factory import ChartDataFactory
-from kerykeion.charts.chart_drawer import ChartDrawer
+from kerykeion import AstrologicalSubject, KerykeionChartSVG
 from typing import Optional, Any, Dict
 import logging
 import io
@@ -125,46 +123,32 @@ async def calculate_chart(req: BirthRequest):
 
 @app.post("/api/generate-chart-svg")
 async def generate_chart_svg(req: BirthRequest):
-    """Generate professional birth chart SVG with aspects"""
+    """Generate professional birth chart SVG with aspects (Kerykeion 4.x)"""
     try:
         logger.info(f"🎨 Generating SVG chart for: {req.name}")
 
         year, month, day = map(int, req.date.split('-'))
         hour, minute = map(int, req.time.split(':'))
 
-        # Use new Kerykeion 5.x API
-        subject = AstrologicalSubjectFactory.from_birth_data(
+        # Create AstrologicalSubject (Kerykeion 4.x)
+        subject = AstrologicalSubject(
             name=req.name,
             year=year, month=month, day=day,
             hour=hour, minute=minute,
-            lng=req.longitude or 0.0,
+            city=req.location,
             lat=req.latitude or 0.0,
+            lng=req.longitude or 0.0,
             tz_str=req.timezone,
             zodiac_type="Tropic",
             houses_system_identifier="P",
             online=False
         )
 
-        # Create chart data
-        chart_data = ChartDataFactory.create_natal_chart_data(subject)
-
-        # Generate SVG
-        chart_drawer = ChartDrawer(chart_data=chart_data)
-
-        # Get SVG content (ChartDrawer internally generates SVG)
-        # We need to save to a temp location then read it
-        import tempfile
-        from pathlib import Path
-
-        with tempfile.TemporaryDirectory() as tmpdir:
-            output_path = Path(tmpdir)
-            chart_drawer.save_svg(output_path=output_path, filename="chart")
-
-            svg_file = output_path / "chart.svg"
-            if not svg_file.exists():
-                raise HTTPException(status_code=500, detail="Failed to generate SVG")
+        # Generate SVG chart (Kerykeion 4.x)
+        chart = KerykeionChartSVG(subject)
 
-            svg_content = svg_file.read_text()
+        # Get SVG content as string
+        svg_content = chart.makeSVG()
 
         logger.info(f"✅ SVG generated for {req.name}")