fix: Bilbo randomness flickering - move random rolls from updateRates() to tick()

updateRates() is called from buyBuilding, buyProject, resolveEvent, sprint
activation, and other non-tick contexts. Having Math.random() inside it caused
the creativity rate to flicker unpredictably whenever ANY of those functions ran.

Fix: roll Bilbo burst/vanish once per tick, store as flags, read flags in
updateRates(). Deterministic rate calculation, consistent randomness.

game.js

@@ -1125,13 +1125,16 @@ function updateRates() {
         G.userRate += 5 * timmyCount * (timmyMult - 1);
     }
 
-    // Bilbo randomness: 10% chance of massive creative burst
-    if (G.buildings.bilbo > 0 && Math.random() < CONFIG.BILBO_BURST_CHANCE) {
-        G.creativityRate += 50 * G.buildings.bilbo;
-    }
-    // Bilbo vanishing: 5% chance of zero creativity this tick
-    if (G.buildings.bilbo > 0 && Math.random() < CONFIG.BILBO_VANISH_CHANCE) {
-        G.creativityRate = 0;
+    // Bilbo randomness: flags are set per-tick in tick(), not here
+    // updateRates() is called from many non-tick contexts (buy, resolve, sprint)
+    // and would cause rate flickering if random rolls happened here
+    if (G.buildings.bilbo > 0) {
+        if (G.bilboBurstActive) {
+            G.creativityRate += 50 * G.buildings.bilbo;
+        }
+        if (G.bilboVanishActive) {
+            G.creativityRate = 0;
+        }
     }
 
     // Allegro requires trust
@@ -1228,6 +1231,17 @@ function tick() {
     G.tick += dt;
     G.playTime += dt;
 
+    // Bilbo randomness: roll once per tick, store as flags for updateRates()
+    // Previously this was inside updateRates() which caused flickering
+    // since updateRates() is called from many non-tick contexts
+    if (G.buildings.bilbo > 0) {
+        G.bilboBurstActive = Math.random() < CONFIG.BILBO_BURST_CHANCE;
+        G.bilboVanishActive = Math.random() < CONFIG.BILBO_VANISH_CHANCE;
+    } else {
+        G.bilboBurstActive = false;
+        G.bilboVanishActive = false;
+    }
+
     // Sprint ability
     tickSprint(dt);