The new 'Only show games available on this platform' checkbox in the
plugin settings drops games whose platforms don't include the OS
OpenGamepadUI is running on (e.g. Windows-only games on Linux). Games
with no platform info at all (HTML5) are kept since there's nothing to
filter on. The setting is read on every library load, so toggling it
reloads the itch.io library without a restart.
Godot JSON.parse decodes every JSON number as a float, so integer ids
(7670) round-trip through JSON.stringify as 7670.0, which Go's int64
fields reject with RPC error -32700. Normalize at the parse boundary so
profile/game/upload ids serialize correctly.
Also drop the nonexistent 'fresh' parameter from Fetch.ProfileOwnedKeys.
