fix: resolve all 8 open bug tickets (#242–#249)

- #242: use formatNumber for crystals in resource bar to respect notation setting
- #243: include current-run gold in companion unlock progress (client + server)
- #244: skip rendering empty reward spans for zero-crystal quest rewards
- #245/#248: skip auto-save while auto-prestige is in-flight to prevent optimistic lock collision
- #246: generate and upload CDN images for crystal_pulse, crystal_surge, crystal_tempest upgrades
- #247: merge daily challenge progress in validateAndSanitize (take max of client vs server) to prevent stale auto-saves rolling back server-side completions
- #249: clear cached signature after buying prestige upgrade to prevent mismatch on next save

apps/web/src/components/game/companionPanel.tsx

@@ -163,7 +163,8 @@ const CompanionPanel = (): JSX.Element => {
   const progressByUnlockType: Record<string, number> = {
     apotheosis:     state.apotheosis?.count ?? 0,
     lifetimeBosses: state.player.lifetimeBossesDefeated,
-    lifetimeGold:   state.player.lifetimeGoldEarned,
+    // eslint-disable-next-line stylistic/max-len -- Long expression; splitting would reduce readability
+    lifetimeGold:   state.player.lifetimeGoldEarned + state.player.totalGoldEarned,
     lifetimeQuests: state.player.lifetimeQuestsCompleted,
     prestige:       state.prestige.count,
     transcendence:  state.transcendence?.count ?? 0,

apps/web/src/components/game/questPanel.tsx

@@ -114,6 +114,9 @@ const QuestCard = ({
         }
         <div className="quest-rewards">
           {quest.rewards.map((reward, rewardIndex) => {
+            if (reward.type === "crystals" && (reward.amount ?? 0) === 0) {
+              return null;
+            }
             return (
               <span className="reward-tag" key={`${reward.type}-${reward.targetId ?? String(reward.amount ?? rewardIndex)}`}>
                 {reward.type === "gold"
@@ -121,7 +124,6 @@ const QuestCard = ({
                 {reward.type === "essence"
                   && `✨ ${formatNumber(reward.amount ?? 0)}`}
                 {reward.type === "crystals"
-                  && (reward.amount ?? 0) > 0
                   && `💎 ${formatNumber(reward.amount ?? 0)}`}
                 {reward.type === "upgrade" && "🔓 Upgrade"}
                 {reward.type === "adventurer" && "👥 New Adventurer"}

apps/web/src/components/ui/resourceBar.tsx

@@ -218,7 +218,7 @@ const ResourceBar = ({
                 : ""}`}>
                 <span className="resource-icon">{"💎"}</span>
                 <span className="resource-value">
-                  {formatInteger(crystals)}
+                  {formatNumber(crystals)}
                 </span>
                 <span className="resource-label">{"Crystals"}</span>
                 {crystalsFull

apps/web/src/context/gameContext.tsx

@@ -1356,10 +1356,11 @@ export const GameProvider = ({
         newlyFailedQuestsReference.current = [];
       }
 
-      // Auto-save every 30 seconds (skip if a force sync is in-flight to avoid signature collisions)
+      // Auto-save every 30 seconds (skip if a force sync or auto-prestige is in-flight to avoid signature collisions)
       if (Date.now() - lastSaveReference.current >= autoSaveIntervalMs) {
         lastSaveReference.current = Date.now();
-        if (stateReference.current !== null && !isSyncingReference.current) {
+        // eslint-disable-next-line stylistic/max-len -- Long condition; splitting would reduce readability
+        if (stateReference.current !== null && !isSyncingReference.current && !isAutoPrestigingReference.current) {
           void saveGame({
             state: stateReference.current,
             ...signatureReference.current === null
@@ -1856,6 +1857,13 @@ export const GameProvider = ({
           },
         };
       });
+
+      /*
+       * Buying a prestige upgrade mutates DB state; clear the cached signature
+       * so the next auto-save doesn't collide with a stale one.
+       */
+      signatureReference.current = null;
+      localStorage.removeItem("elysium_save_signature");
     } catch (error_: unknown) {
       logError("buy_prestige_upgrade", error_);
       // Silently ignore — server errors shouldn't crash the UI