Marks and dig selection in each master's colour; imps dig only their master's marks; AI marks near its ground, acts calmer, re-summons imps; allies never claim each other's ground

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

src/main.rs

@@ -2097,7 +2097,11 @@ fn draw_frame(app: &mut App, gfx: &Gfx, r3d: &mut R3d, ui: &mut Ui, menu: &mut M
     let ground = app.cam.ground_point(mx, my);
     clear_background(Color::from_rgba(4, 3, 5, 255));
     let (color, radius) = match ui.tool {
-        Tool::Dig => (Color::new(1.0, 0.85, 0.3, 1.0), None),
+        Tool::Dig => {
+            // the dig selection in the master's colour (like the marks)
+            let c = render3d::master_rgb(app.game.local_side);
+            (Color::new(c.x, c.y, c.z, 1.0), None)
+        }
         Tool::Hand => (Color::new(0.9, 0.75, 0.6, 1.0), None),
         Tool::Room(_) => (Color::new(0.4, 0.85, 1.0, 1.0), None),
         Tool::Sell => (Color::new(1.0, 0.5, 0.3, 1.0), None),