Show total items to scan in progress overlay

- Add total_items parameter to broadcast_scan_started and broadcast_scan_progress
- Pass total from SeriesApp to WebSocket broadcasts in AnimeService
- Update JS overlay to show progress bar and current/total count
- Add CSS for progress bar styling
- Add unit tests for new total_items parameter
- All 1024 tests passing

src/core/SeriesApp.py

@@ -446,12 +446,17 @@ class SeriesApp:
 
         try:
             # Get total items to scan
+            logger.info("Getting total items to scan...")
             total_to_scan = await asyncio.to_thread(
                 self.serie_scanner.get_total_to_scan
             )
             logger.info("Total folders to scan: %d", total_to_scan)
 
             # Fire scan started event
+            logger.info(
+                "Firing scan_status 'started' event, handler=%s",
+                self._events.scan_status
+            )
             self._events.scan_status(
                 ScanStatusEventArgs(
                     current=0,
@@ -502,6 +507,10 @@ class SeriesApp:
             logger.info("Directory rescan completed successfully")
 
             # Fire scan completed event
+            logger.info(
+                "Firing scan_status 'completed' event, handler=%s",
+                self._events.scan_status
+            )
             self._events.scan_status(
                 ScanStatusEventArgs(
                     current=total_to_scan,