fix: Add locks, logging refactor, and bugfixes

Improve thread-safety, logging, and various bug fixes across the app.

Key changes:
- Add and use state.downloads_lock around accesses to state.active_downloads in multiple modules (UI, libtorrent, misc, direct downloads) to prevent race conditions.
- Prevent concurrent dl_status_loop runs using a non-blocking _loop_lock and ensure proper iteration over a snapshot of downloads.
- Add metadata timeout when waiting for torrent metadata and fix free-space check logic to remove or reject downloads appropriately.
- Refactor download log persistence: add _load_downloads and _save_downloads helpers and centralize JSON read/write logic in utils/logging/logs.py.
- Optimize DirectDownloadStatus speed window by switching to deque and using popleft to trim older samples.
- Trim console log widget to 500 lines to avoid unbounded growth.
- Add small state fields for custom image positioning (x/y and enabled flag).
- Fix Steamrip scraper caching behavior and make Uztracker return an empty list on fetch failures.
- Add defensive checks in run_download to handle missing links.

These changes focus on stability and correctness for concurrent download handling and durable logging.

src/network/direct_download/__init__.py

@@ -15,9 +15,10 @@ def add_direct_download(url: str, title: str, dl_path: Optional[str] = None, hea
     if dl_path is None:
         dl_path = state.download_path
 
-    if url in state.active_downloads:
-        consoleLog(f"Download already active: {title}")
-        return
+    with state.downloads_lock:
+        if url in state.active_downloads:
+            consoleLog(f"Download already active: {title}")
+            return
 
     filename = (
         detect_filename_from_headers(url, DirectDownloadHandle.USER_AGENT)
@@ -26,7 +27,8 @@ def add_direct_download(url: str, title: str, dl_path: Optional[str] = None, hea
     )
 
     handle = DirectDownloadHandle(url, filename, dl_path, headers, single_threaded)
-    state.active_downloads[url] = handle
+    with state.downloads_lock:
+        state.active_downloads[url] = handle
     add_download_log(title, url, "", False)
     handle.start()
     consoleLog(f"Started direct download: {filename}")