Fix production issues: add matplotlib dep, fix get_db calls, resolve ESLint

- Add matplotlib>=3.7.0 to requirements-podcast.txt (B-roll requires it)
- Fix research.py and exa_provider.py using get_session_for_user() instead of broken Depends(get_db)
- Fix BrollInfoPanel.tsx: call useScriptEditor hook unconditionally
- Add debug logging to avatar endpoint for troubleshooting

backend/services/podcast/broll_composer.py

@@ -8,11 +8,11 @@ import numpy as np
 from pathlib import Path
 from dataclasses import dataclass, field
 from typing import Optional
+from PIL import Image, ImageDraw, ImageFont
 import matplotlib
 matplotlib.use("Agg")
 import matplotlib.pyplot as plt
 import matplotlib.patches as mpatches
-from PIL import Image, ImageDraw, ImageFont
 from moviepy import (
     VideoFileClip, ImageClip, CompositeVideoClip,
     concatenate_videoclips,