Add Demoio directory for test videos with 8-day retention; capture gap warning

daily_sunrise_video.sh:
- Test output now saves to DEMO_DIR/<cam>/ (default: MOVIES_DIR/demoio/<cam>/)
  instead of the production sunrise-only directory
- After each test run, deletes test files older than DEMO_RETENTION_DAYS (8)
- Production mode: warns if the last selected frame is >3 intervals before
  the window end, which indicates the capture service had a gap near sunrise:
    WARNING: last frame is 20min 0s before window end — capture gap near sunrise
             Check: systemctl --user status sky-cam-capture-east.service

sky-cam.conf: add DEMO_DIR and DEMO_RETENTION_DAYS settings

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

daily_sunrise_video.sh

@@ -114,6 +114,15 @@ first_t=$(basename "${images[0]}"  .jpg | tr '-' ':')
 last_t=$(basename  "${images[-1]}" .jpg | tr '-' ':')
 echo "Images: ${#images[@]}  (${first_t} → ${last_t}  overlay: ${SR_TIME})"
 
+if ! $TEST_MODE; then
+    last_sec=$(time_to_seconds "$(basename "${images[-1]}" .jpg)")
+    gap=$(( end_sec - last_sec ))
+    if [ "$gap" -gt $(( ${CAPTURE_INTERVAL:-10} * 3 )) ]; then
+        echo "WARNING: last frame is $(( gap / 60 ))min ${gap}s before window end — capture gap near sunrise"
+        echo "         Check: systemctl --user status sky-cam-capture-${CAM_NAME}.service"
+    fi
+fi
+
 # Concat list with explicit frame duration so each frame represents real elapsed
 # time.  Without this, all frames collapse to timestamp 0 → one-frame video.
 # The final entry needs a duplicate without duration (ffmpeg concat requirement).
@@ -261,7 +270,9 @@ fi
 #   audio ✗  overlay ✓  → final has overlay, no audio
 #   audio ✗  overlay ✗  → sped video promoted (no audio, no overlay)
 if $TEST_MODE; then
-    final_video="$output_dir/$current_date-daily-sunrise-test.mp4"
+    demo_dir="${DEMO_DIR:-$MOVIES_DIR/demoio}/$CAM_NAME"
+    mkdir -p "$demo_dir"
+    final_video="$demo_dir/$current_date-daily-sunrise-test.mp4"
 else
     final_video="$output_dir/$current_date-daily-sunrise.mp4"
 fi
@@ -334,7 +345,17 @@ if $step3b_ok; then
     echo "Done: $final_video  (${actual_dur}s, time: ${SR_TIME})"
     rm -f "$sped_video" "$temp_audio" 2>/dev/null || true; temp_audio=""
 
-    if ! $TEST_MODE; then
+    if $TEST_MODE; then
+        # ── Demo retention ────────────────────────────────────────────────────
+        demo_retain="${DEMO_RETENTION_DAYS:-8}"
+        if [ "$demo_retain" -gt 0 ]; then
+            deleted_demo=$(find "${DEMO_DIR:-$MOVIES_DIR/demoio}" \
+                -name "*-daily-sunrise-test.mp4" \
+                -mtime +"$demo_retain" -print -delete 2>/dev/null | wc -l)
+            [ "$deleted_demo" -gt 0 ] && \
+                echo "Demo retention: deleted $deleted_demo test file(s) older than ${demo_retain} days"
+        fi
+    else
         [ -f "${cam_audio:-}" ] && rm -f "${cam_audio:-}"
         "$SCRIPT_DIR/notify.sh" "Sunrise ready: $current_date" \
             "$(basename "$final_video") — ${actual_dur}s, sunrise at ${SR_TIME} | $final_video" || true

sky-cam.conf

@@ -228,6 +228,10 @@ SUNRISE_RETENTION_DAYS=10
 # Delete unpinned sunrise posts from Mattermost older than this many days.
 # Pinned posts are always kept regardless.  Set 0 to disable Mattermost cleanup.
 MM_SUNRISE_RETENTION_DAYS=8
+# Output directory for --test runs.  Kept separate from production sunrise videos.
+# Test files older than DEMO_RETENTION_DAYS are deleted automatically.
+DEMO_DIR="${DEMO_DIR:-$MOVIES_DIR/demoio}"
+DEMO_RETENTION_DAYS=8
 
 # ── Video encoding quality ────────────────────────────────────────────────────
 # FFmpeg CRF: lower = higher quality / larger files.  Typical range 18–30.