Fourth master: dwarves get their own side so the yellow AI works; yellow colours and texts; AI cores use the player's throne and heart in their colour

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/save.rs

@@ -52,6 +52,12 @@ pub fn from_bytes(data: &[u8]) -> Result<Loaded, &'static str> {
         return Err("save.err_version");
     }
     let mut game = s.game;
+    // older saves kept the dwarves on side 4, which is now the fourth master
+    if !game.is_master(4) && !game.rivals.iter().any(|r| r.side == 4) {
+        for e in game.ents.iter_mut().filter(|e| !e.hero && e.side == 4) {
+            e.side = crate::dwarves::DWARF_SIDE;
+        }
+    }
     game.map.activate();
     game.recount();
     Ok(Loaded { game, camera: s.camera })