Session 15: Buy Max Prestige Upgrades (bulk-buy for prestige upgrades) + fix missing Stellar Essence spend

js/prestigeUI.js

@@ -43,6 +43,15 @@ const PrestigeUI = {
                 }
             });
         });
+
+        // Buy Max prestige upgrades button - buy every affordable prestige
+        // upgrade at once, paid from Stellar Essence.
+        const buyMaxBtn = document.getElementById('buy-all-prestige');
+        if (buyMaxBtn) {
+            buyMaxBtn.addEventListener('click', () => {
+                Game.buyMaxPrestigeUpgrades();
+            });
+        }
     },
 
     /**
@@ -119,7 +128,44 @@ const PrestigeUI = {
         if (prestigeTab?.classList.contains('active')) {
             this.renderPrestigeUpgrades();
         }
-    }
+
+        // Show/hide the "Buy Max" button based on whether any unowned prestige
+        // upgrade is currently affordable with Stellar Essence. Read-only.
+        this.updateBuyMaxPrestigeButton();
+    },
+
+    /**
+     * Show/hide and enable/disable the "Buy Max" prestige-upgrades button
+     * depending on whether at least one unowned, requirement-met prestige
+     * upgrade is currently affordable with Stellar Essence. Read of game state
+     * only; never mutates it. Mirrors Game.buyMaxPrestigeUpgrades /
+     * PRESTIGE.buyUpgrade semantics.
+     */
+    updateBuyMaxPrestigeButton() {
+        const btn = document.getElementById('buy-all-prestige');
+        if (!btn) return;
+
+        let affordableAny = false;
+        for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+            if ((Game.state.prestigeUpgrades || []).includes(id)) continue;
+            if ((Game.state.stellarEssence || 0) < upgrade.cost) continue;
+            if (upgrade.requirements) {
+                let met = true;
+                for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                    if ((Game.state.buildings[reqId] || 0) < reqCount) {
+                        met = false;
+                        break;
+                    }
+                }
+                if (!met) continue;
+            }
+            affordableAny = true;
+            break;
+        }
+
+        btn.style.display = affordableAny ? '' : 'none';
+        btn.disabled = !affordableAny;
+    },
 };
 
 window.PrestigeUI = PrestigeUI;