Fix first-run blockers: MOVIES_DIR path, CAM_NAME, .env for Python, eval safety

daily_sunrise_video.sh: use \$MOVIES_DIR instead of \$BASE_DIR/movies so the
override in sky-cam.conf is respected when videos live on a separate drive.

capture.sh: default camera name falls back to \$SUNRISE_CAM (not the
undefined \$CAM_NAME) when no argument is passed.

sunrise2mm.py: also loads .env after sky-cam.conf so Mattermost credentials
moved to .env are actually visible to the upload script.

sunrise.py: raise a clear error message when LATITUDE/LONGITUDE/TIMEZONE
are missing from sky-cam.conf instead of an opaque KeyError.

4-seasons.sh, montage-mvt.sh: capture season_info.py output before eval so
a Python failure exits cleanly with a diagnostic message rather than
silently continuing with undefined variables.

bootstrap.sh: add system package install step (ffmpeg bc fonts-dejavu) and
show the .env setup step after install.sh generates .env.example.

README.md: correct Python package names and add fonts-dejavu dependency.

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

README.md

@@ -13,7 +13,8 @@ Automated sky / timelapse camera scripts that produce:
 | Dependency | Notes |
 |---|---|
 | `ffmpeg` + `ffprobe` | Encoding, capture, audio recording, duration probing |
-| `python3` | `ephem` package for sunrise calculation, `requests` for Mattermost upload |
+| `python3` | `suntime pytz` for sunrise calculation, `requests` for Mattermost upload — `pip3 install suntime pytz requests` |
+| `fonts-dejavu` | DejaVu fonts for text overlays — `sudo apt install fonts-dejavu` |
 | `bc` | Shell arithmetic (floating-point speed factors) |
 | `fontconfig` (`fc-match`) | Font detection for overlays — optional, falls back to hardcoded paths |
 | IP camera with RTSP stream | `capture.sh` pulls frames directly — no NVR software needed |