Sunrise time overlay; systemd upload separation; bug fixes

daily_sunrise_video.sh:
- Fixed: was using undefined \$MOVIES_DIR (now \$BASE_DIR/movies)
- Fixed: sunrise_overlay.py was called but never existed — would fail daily
- Fixed: speed-adjust step had no explicit codec (-c:v libx264 missing)
- New: sunrise time overlaid as stacked vertical characters on the right
  side using ffmpeg drawtext — no Python/Pillow dependency
- New: upload removed from script; now triggered by systemd OnSuccess=
- Combines speed-adjust and overlay into one ffmpeg pass (was two)
- SUNRISE_OVERLAY_OPACITY from conf controls transparency

install.sh:
- sky-cam-sunrise.service gains OnSuccess=sky-cam-sunrise-upload.service
  so upload only runs when video creation succeeds, with separate log
- New sky-cam-sunrise-upload.service runs sunrise2mm.py

sunrise2mm.py: add shebang + chmod +x so systemd ExecStart= calls it directly

sky-cam.conf: add SUNRISE_OVERLAY_OPACITY=0.45

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

sky-cam.conf

@@ -204,6 +204,8 @@ SUNRISE_PRE_MIN=70
 SUNRISE_POST_MIN=10
 # Target duration (seconds) for the speed-adjusted sunrise video.
 SUNRISE_TARGET_SECS=10
+# Opacity of the sunrise-time overlay (0.0 = invisible, 1.0 = fully opaque).
+SUNRISE_OVERLAY_OPACITY=0.45
 
 # ── Full-day timelapse tuning ─────────────────────────────────────────────────
 FULLDAY_FPS=5        # frame rate of the timelapse video