refactor: migrate main.py to modular routers and add project roadmap

- Migrated monolithic main.py to feature-scoped routers in app/routers/
- Added GEMINI.md for project context and AI instructional guidelines
- Updated README.md with a comprehensive modernization plan (SQL migration, robust scraping DSL, frontend modernization)
- Improved authentication with cookie support and modular JS
- Updated test suite and documentation

app/downloaders/video_players/__init__.py

@@ -12,6 +12,7 @@ from .rapidfile import RapidFileDownloader
 from .vidzy import VidzyDownloader
 from .luluv import LuLuvidDownloader
 from .uqload import UqloadDownloader
+from .smoothpre import SmoothpreDownloader
 
 __all__ = [
     "BaseVideoPlayer",
@@ -26,6 +27,7 @@ __all__ = [
     "VidzyDownloader",
     "LuLuvidDownloader",
     "UqloadDownloader",
+    "SmoothpreDownloader",
 ]
 
 
@@ -43,6 +45,7 @@ def get_video_player(url: str) -> BaseVideoPlayer:
         VidzyDownloader(),
         LuLuvidDownloader(),
         UqloadDownloader(),
+        SmoothpreDownloader(),
     ]
 
     for player in players: