Converter: cover real Ren'Py games better, add folder import and dry run

Checked against six real games (Ren'Py 7.5 and 8.x):
- nested labels and named menus become jump anchors inside label bodies
- call with arguments and labels with parameters (dynamically scoped)
- frame-by-frame ATL images, Movie frames, layeredimage, camera, Shake,
  custom audio channels via register_channel, show text with expressions
- generator expressions in Python, no SyntaxWarning noise from decompiled code

Also:
- app.import_dir converts an unpacked game folder without changing it
- app.converter.analyze dry-runs the script part of the converter
- imports use their own "importing" status so a worker restart can't hijack them

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/app/worker.py

@@ -3,6 +3,7 @@
 import asyncio
 import logging
 import shutil
+from pathlib import Path
 
 from sqlalchemy import select, update
 
@@ -41,34 +42,39 @@ async def claim() -> GameVersion | None:
 
 
 async def process(v: GameVersion) -> None:
-    settings = get_settings()
+    ok = await convert(v.id, upload_path(v.id), v.upload_name or "")
+    if ok:
+        remove_upload(v.id)  # sources are not kept once converted
+
+
+async def convert(version_id: int, source: Path, filename: str) -> bool:
+    """Run the converter for a version and store the outcome. Returns success."""
     loop = asyncio.get_running_loop()
-    work = settings.work_dir / str(v.id)
+    work = get_settings().work_dir / str(version_id)
 
     def progress(text: str) -> None:
-        asyncio.run_coroutine_threadsafe(set_progress(v.id, text), loop)
+        asyncio.run_coroutine_threadsafe(set_progress(version_id, text), loop)
 
-    log.info("converting version %s (%s)", v.id, v.upload_name)
+    log.info("converting version %s (%s)", version_id, filename)
     try:
-        result = await asyncio.to_thread(convert_archive, upload_path(v.id), v.upload_name or "",
-                                         work, progress)
+        result = await asyncio.to_thread(convert_archive, source, filename, work, progress)
     except Exception as e:  # noqa: BLE001
-        log.exception("version %s failed", v.id)
+        log.exception("version %s failed", version_id)
         async with SessionLocal() as db:
-            version = await db.get(GameVersion, v.id)
+            version = await db.get(GameVersion, version_id)
             if version:
                 version.status = "failed"
                 version.progress = f"Ошибка: {e}"[:255]
                 version.report = {"error": str(e)}
                 await db.commit()
-        return
+        return False
     finally:
         shutil.rmtree(work, ignore_errors=True)
 
     async with SessionLocal() as db:
-        version = await db.get(GameVersion, v.id)
+        version = await db.get(GameVersion, version_id)
         if version is None:  # deleted while converting
-            return
+            return True
         version.status = "ready"
         version.progress = ""
         version.manifest = result.manifest
@@ -81,9 +87,11 @@ async def process(v: GameVersion) -> None:
                                                           read_bytes(result.cover_source))
             except OSError:
                 pass
+        if game and result.title and game.title == source.name:
+            game.title = result.title
         await db.commit()
-    remove_upload(v.id)  # sources are not kept once converted
-    log.info("version %s ready: %s", v.id, result.report.get("media"))
+    log.info("version %s ready: %s", version_id, result.report.get("media"))
+    return True
 
 
 async def main() -> None: