Move location/music/ntfy config to .env; add paths to notifications

sky-cam.conf:
- MUSIC_DIR now uses override pattern (MUSIC_DIR="${MUSIC_DIR:-$SCRIPT_DIR/music}")
  so the real path can be set in .env without hardcoding it
- LATITUDE/LONGITUDE use override pattern; set real coords in .env to keep
  location private and out of git
- NTFY_URL now uses override pattern with empty default; set in .env
- NTFY_ENABLED moved out of comments into active config with false default

sunrise.py:
- Reads .env after sky-cam.conf so .env values override (same source order
  as sky-cam.conf itself)
- Handles ${VAR:-default} bash syntax when parsing sky-cam.conf values

All completion notifications now include the full output file path so you
can tell at a glance where the file landed:
- daily_sunrise_video.sh: "filename — Xs, sunrise at HH:MM | /full/path"
- 4-seasons.sh: "filename — Xs | /full/path"
- montage-mvt.sh: "filename | checks | /full/path | verify: ..."
- year-end-join.sh: "filename — Xmin | /full/path" (also adds [cam] to title)

install.sh .env.example now includes LATITUDE, LONGITUDE, MUSIC_DIR, NTFY_URL

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

4-seasons.sh

@@ -131,7 +131,7 @@ if awk "BEGIN{exit !($drift > 0.5)}"; then
 fi
 
 "$SCRIPT_DIR/notify.sh" "[$CAM_NAME] $SEASON Mvt$MVT_NUM Day$DAY_OF_MVT/$DAYS_IN_MVT saved ($yesterday)" \
-    "$(basename "$final_file") — ${adjusted}s" || true
+    "$(basename "$final_file") — ${adjusted}s | $final_file" || true
 
 # ── Auto-trigger montage on last day of movement ──────────────────────────────
 if [ "$IS_LAST_DAY" = "true" ]; then