Reset Timer Doodad + Various Fixes

* Bird is not solid when colliding with other birds.
* If the dev shell is used to run JavaScript during Play Mode, consider
  it cheating (so player can't `$ d.Scene.ResetTimer()` for example)
* On Survival Mode levels, DieByFire immediately opens the End Level
  (silver score) modal rather than respawn from checkpoint, so levels
  don't need checkpoint contraptions to end the level.
* During level loading screens, wait and call doodads' main() function
  until the very end.

dev-assets/doodads/bird/bird.js

@@ -31,7 +31,7 @@ function main() {
 			return;
 		}
 
-		if (e.Actor.IsMobile() && e.InHitbox) {
+		if (e.Actor.IsMobile() && e.Actor.HasGravity() && e.InHitbox) {
 			return false;
 		}
 	});

dev-assets/doodads/regions/Makefile

@@ -28,6 +28,10 @@ build:
 	doodad edit-doodad --tag "color=invisible" reg-warp-door.doodad
 	doodad install-script ../warp-door/warp-door.js reg-warp-door.doodad
 
+	# Reset Level Timer
+	doodad convert -t "Reset Level Timer" timer-64.png reg-reset-timer.doodad
+	doodad install-script reset-timer.js reg-reset-timer.doodad
+
 	for i in *.doodad; do\
 		doodad edit-doodad --tag "category=technical" $${i};\
 	done

dev-assets/doodads/regions/reset-timer.js

@@ -0,0 +1,30 @@
+// Reset Level Timer.
+function main() {
+    Self.Hide();
+
+    // Reset the level timer only once.
+    let hasReset = false;
+
+    Events.OnCollide((e) => {
+        if (!e.Settled) {
+            return;
+        }
+
+        // Only care if it's the player.
+        if (!e.Actor.IsPlayer()) {
+            return;
+        }
+
+        if (e.InHitbox && !hasReset) {
+            Level.ResetTimer();
+            hasReset = true;
+        }
+    });
+
+    // Receive a power signal resets the doodad.
+    Message.Subscribe("power", (powered) => {
+        if (powered) {
+            hasReset = true;
+        }
+    });
+}