Update cloud sync integrations

[ribbit384]

• Fixes Steam Auto Cloud conflict handling so first-run local saves upload instead of being treated as a conflict.
• Uses remote Steam cloud baselines when local file-change metadata is unavailable.
• Adds Steam upload preflight checks for file count, quota, and the 100 MB per-file limit.
• Skips unsupported Steam cloud roots and fixes %root_mod% parsing.
• Treats forced Steam downloads with UpToDate results as successful.
• Moves Steam cloud sync launch, exit, helper, and conflict UI code into a dedicated Steam cloud sync package.
• Reworks the cloud conflict dialog into a compact Steam-styled UI with the Steam UI in a separate file.
• Keeps real Steam launch/remotecache cleanup gated by cloud sync and offline settings.
• Updates Google Drive-backed save history and store-login sync to use explicit Drive authorization paths.
• Defers Google store-login auto backup to explicit settings actions and adds cached/remote refresh separation.
• Validated with ./gradlew.bat :app:compileStandardDebugKotlin :app:compileStandardDebugJavaWithJavac.