feat: unlock in-game galleries per owned version

backend/app/gallery.py

@@ -0,0 +1,22 @@
+"""Gallery support for converted games; never changes scripts or story progress."""
+from app.translation import file_json
+
+
+def available(manifest: dict | None) -> bool:
+    if not manifest or "game.json" not in manifest.get("files", {}):
+        return False
+    game = file_json(manifest, "game.json")
+    if game.get("engine") not in (None, "renpy") or game.get("runtime"):
+        return False
+    screens = game.get("screens", {})
+    if game.get("build", {}).get("name") == "MIST" and "rewatchgirlselectscreen" in screens:
+        return True
+
+    def uses_gallery(value):
+        if isinstance(value, dict):
+            if value.get("k") == "call" and value.get("f", {}).get("k") == "name" and value["f"].get("id") in {"Gallery", "Replay"}:
+                return True
+            return any(uses_gallery(item) for item in value.values())
+        return isinstance(value, list) and any(uses_gallery(item) for item in value)
+
+    return uses_gallery(game.get("init", [])) or uses_gallery(screens) or uses_gallery(game.get("defaults", []))