capture.sh: source .env so RTSP credentials are available

CAM_RTSP_<cam> is set in .env, not sky-cam.conf, but capture.sh was
only sourcing sky-cam.conf — causing the service to fail with "not set"
even after credentials were added to .env.

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

capture.sh

@@ -15,6 +15,7 @@ set -euo pipefail
 
 SCRIPT_DIR="$(dirname "$(realpath "$0")")"
 source "$SCRIPT_DIR/sky-cam.conf"
+source "$SCRIPT_DIR/.env" 2>/dev/null || true
 export TZ="$TIMEZONE"
 
 CAM="${1:-}"
@@ -26,7 +27,7 @@ fi
 rtsp_var="CAM_RTSP_${CAM}"
 RTSP_URL="${!rtsp_var:-}"
 if [ -z "$RTSP_URL" ]; then
-    echo "ERROR: CAM_RTSP_${CAM} not set in sky-cam.conf"
+    echo "ERROR: CAM_RTSP_${CAM} not set in .env"
     exit 1
 fi