Hearthstone deck tracker for Linux, first public version

Reads the game's own Power.log: no screen capture, no image
recognition, no memory reading.

- deck tracking (remaining cards, draw chance, played cards fade in place)
- opponent panel (revealed cards, hand and deck counts)
- decks read from the game's offline cache, matched to the match
- card art in rows, full card on hover
- overlay and window modes, adjustable transparency, tray icon
- English and Turkish interface
- consistency tests over a real log corpus, cross-checked against Zone.log

data/images.py

@@ -0,0 +1,92 @@
+"""Kart görselleri: art.hearthstonejson.com'dan indirir, diske önbelleğe alır.
+
+İki boyut kullanılıyor:
+    tile   256x59  kart satırının arka planındaki sanat şeridi
+    render 256x388 fareyle üzerine gelince gösterilen tam kart (metni dahil)
+
+İndirmeler arka plan iş parçacıklarında yapılır, arayüz beklemez. Yeni bir
+görsel hazır olduğunda `generation` sayacı artar; arayüz bu sayacı izleyip
+kendini tazeler. Böylece Qt sinyali gerekmiyor ve bu modül stdlib kalıyor.
+"""
+
+from __future__ import annotations
+
+import os
+import threading
+import urllib.error
+import urllib.request
+from concurrent.futures import ThreadPoolExecutor
+from pathlib import Path
+
+TILE_URL = "https://art.hearthstonejson.com/v1/tiles/{card_id}.png"
+RENDER_URL = "https://art.hearthstonejson.com/v1/render/latest/enUS/256x/{card_id}.png"
+USER_AGENT = "deste/0.1 (kisisel hearthstone tracker; +local)"
+
+CACHE_DIR = Path(os.environ.get("XDG_CACHE_HOME", "~/.cache")).expanduser() / "deste" / "images"
+
+TILE = "tile"
+RENDER = "render"
+
+
+class ImageCache:
+    def __init__(self, max_workers: int = 4):
+        self.generation = 0
+        self._lock = threading.Lock()
+        self._pending: set[tuple[str, str]] = set()
+        self._failed: set[tuple[str, str]] = set()
+        self._pool = ThreadPoolExecutor(max_workers=max_workers, thread_name_prefix="deste-img")
+        for kind in (TILE, RENDER):
+            (CACHE_DIR / kind).mkdir(parents=True, exist_ok=True)
+
+    def path_for(self, card_id: str, kind: str = TILE) -> Path:
+        return CACHE_DIR / kind / f"{card_id}.png"
+
+    def get(self, card_id: str, kind: str = TILE) -> Path | None:
+        """Görsel diskteyse yolunu döner, değilse indirmeye alır ve None döner."""
+        if not card_id:
+            return None
+        path = self.path_for(card_id, kind)
+        if path.exists():
+            return path
+        key = (card_id, kind)
+        with self._lock:
+            if key in self._pending or key in self._failed:
+                return None
+            self._pending.add(key)
+        self._pool.submit(self._download, card_id, kind)
+        return None
+
+    def prefetch(self, card_ids, kind: str = TILE) -> None:
+        for card_id in card_ids:
+            self.get(card_id, kind)
+
+    def _download(self, card_id: str, kind: str) -> None:
+        url = (TILE_URL if kind == TILE else RENDER_URL).format(card_id=card_id)
+        key = (card_id, kind)
+        try:
+            request = urllib.request.Request(url, headers={"User-Agent": USER_AGENT})
+            with urllib.request.urlopen(request, timeout=20) as response:
+                payload = response.read()
+        except (urllib.error.URLError, TimeoutError, OSError):
+            with self._lock:
+                self._pending.discard(key)
+                self._failed.add(key)
+            return
+
+        path = self.path_for(card_id, kind)
+        try:
+            tmp = path.with_suffix(".tmp")
+            tmp.write_bytes(payload)
+            tmp.replace(path)
+        except OSError:
+            with self._lock:
+                self._pending.discard(key)
+                self._failed.add(key)
+            return
+
+        with self._lock:
+            self._pending.discard(key)
+            self.generation += 1
+
+    def shutdown(self) -> None:
+        self._pool.shutdown(wait=False, cancel_futures=True)