Release candidate: Godot 4.7 RC 1

Godot 4.7 has reached RC1, so the feature set is locked and the focus is now on regression hunting. For teams already on 4.x, the practical takeaway is that this is a reasonable time to start testing upgrades, especially if you care about HDR output, the new Asset Store, or rendering fixes. The usual RC warning applies: back up first and expect to file bugs.