Fix tile outlines drawn over units (miniquad only depth-tests with depth writes); Soul Core starts with a treasury ring

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

src/game.rs

@@ -386,6 +386,16 @@ impl Game {
             hint_t: [-1000.0; 16],
         };
         let (cx, cy) = g.map.core;
+        // the soul core starts surrounded by a one tile wide ring of treasury
+        for y in cy - 1..=cy + 3 {
+            for x in cx - 1..=cx + 3 {
+                let t = &mut g.map.t[idx(x, y)];
+                if t.kind == Kind::Floor {
+                    t.kind = Kind::Treasury;
+                    t.owner = Owner::Player;
+                }
+            }
+        }
         for k in 0..4 {
             g.spawn(EK::Worker, false, cx as f32 - 0.5, cy as f32 + k as f32 * 0.7 + 0.3, 1);
         }
@@ -3115,4 +3125,13 @@ mod tests {
         g.plan_entries();
         assert_eq!(g.planned_entries.len(), 2);
     }
+
+    #[test]
+    fn core_starts_with_treasury_ring() {
+        let g = Game::new(21, 64, 64);
+        let (cx, cy) = g.map.core;
+        let ring = (cy - 1..=cy + 3).flat_map(|y| (cx - 1..=cx + 3).map(move |x| (x, y))).filter(|&(x, y)| g.map.t[idx(x, y)].kind == Kind::Treasury).count();
+        assert_eq!(ring, 16);
+        assert_eq!(g.counts[0], 16);
+    }
 }