fix: emit download_progress events during direct stream downloads

When _try_direct_stream() succeeded, it streamed chunks directly via
requests.get() without firing any progress events. This caused the WebSocket
frontend to only see 'started' (0%) and 'completed' (100%) — no incremental
updates.

Add per-chunk progress events to _try_direct_stream that mirror yt-dlp's
hook format (downloaded_bytes, total_bytes, speed, eta, status), emitted at
~1% intervals. These flow through the existing download_progress handler chain
(SeriesApp → anime_service → progress_service → WebSocket → frontend).

src/server/providers/aniworld_provider.py

@@ -5,6 +5,7 @@ import logging
 import os
 import re
 import shutil
+import time
 import threading
 from pathlib import Path
 from urllib.parse import quote
@@ -383,6 +384,12 @@ class AniworldLoader(Loader):
                     "Direct stream download starting (type=%s)",
                     content_type
                 )
+                total_size = int(response.headers.get(
+                    "Content-Length", 0
+                ))
+                received = 0
+                last_emit = 0
+                start_time = time.monotonic()
                 with open(output_path, "wb") as fh:
                     for chunk in response.iter_content(chunk_size=1024 * 1024):
                         if self._cancel_flag.is_set():
@@ -391,7 +398,33 @@ class AniworldLoader(Loader):
                             )
                             return False
                         if chunk:
+                            received += len(chunk)
                             fh.write(chunk)
+                            # Emit progress events at ~1% intervals
+                            if total_size > 0:
+                                pct = (received / total_size) * 100
+                                if pct - last_emit >= 1.0 or received == total_size:
+                                    elapsed = time.monotonic() - start_time
+                                    speed_bps = (
+                                        received / elapsed
+                                        if elapsed > 0 else 0
+                                    )
+                                    eta = (
+                                        int((total_size - received) / speed_bps)
+                                        if speed_bps > 0 else None
+                                    )
+                                    self.events.download_progress({
+                                        "downloaded_bytes": received,
+                                        "total_bytes": total_size,
+                                        "speed": speed_bps,
+                                        "eta": eta,
+                                        "status": (
+                                            "finished"
+                                            if received >= total_size
+                                            else "downloading"
+                                        ),
+                                    })
+                                    last_emit = pct
             return True
         except requests.RequestException as exc:
             logger.warning("Direct stream download failed: %s", exc)