feat: Switch to patch-first user flow

[CnC-Robert]

Currently, the app determines a default version at the start of the flow by calculating the most compatible version across all available patches. Patch selection is then restricted to this version. Overriding the version requires manually selecting an APK with a specific version, even though it's not clear to the user which versions are supported.

Instead, the flow should be patch-first. Users explicitly select the patches they want, and the manager automatically calculates the most compatible version based on that patch selection. The calculated version can still be manually overridden to a specific version. Once a version is chosen or calculated, the app automatically determines the best APK source corresponding to that version.

Motivation

• Enable version changes directly within the app
• Avoid restricting patch selection based on a preselected version
• Reduce cognitive load by clearly separating patch, version and source selection

Should close #2660, #2504, #2620, #2535