fix: resolve all 8 open bug tickets (#242–#249) (#250)

## Summary

- **#242** — Crystals in the resource bar now use `formatNumber` to respect the player's notation setting (suffix/scientific/engineering)
- **#243** — Companion unlock progress includes current-run gold (`totalGoldEarned`) on both client and server, so companions unlock at the correct threshold
- **#244** — Empty green reward bubbles no longer render for quest crystal rewards with a zero amount
- **#245/#248** — Auto-save skips when `isAutoPrestigingReference.current` is true, preventing it from racing with an in-flight prestige and breaking the optimistic lock
- **#246** — Generated and uploaded CDN images for `crystal_pulse`, `crystal_surge`, and `crystal_tempest` upgrades
- **#247** — `validateAndSanitize` merges daily challenge progress by taking the max of client vs. server progress per challenge, so stale auto-saves can no longer roll back server-side completions
- **#249** — Cached save signature is cleared after `buyPrestigeUpgrade` succeeds, preventing a stale-signature mismatch on the next auto-save

## Test plan

- [ ] Lint passes (`pnpm lint`)
- [ ] Build passes (`pnpm build`)
- [ ] Tests pass with 100% coverage (`pnpm test`)
- [ ] Crystals display in resource bar respects notation setting
- [ ] No empty reward bubbles on quests that don't award crystals
- [ ] Companion progress bar shows correct value including current-run gold
- [ ] Auto-prestige no longer causes save errors
- [ ] Crafting a recipe updates daily challenge progress persistently (not rolled back by next auto-save)
- [ ] Buying a prestige upgrade does not cause a signature mismatch error on next save
- [ ] Crystal upgrade images display correctly in-game

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #250
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/api/src/routes/game.ts

@@ -681,6 +681,45 @@ const validateAndSanitize = (
     storySpread = { story: previous.story };
   }
 
+  /*
+   * Merge daily challenge progress: take the maximum progress for each
+   * challenge so a stale auto-save arriving after a craft/boss/etc. update
+   * cannot silently roll back server-side challenge completions.
+   */
+  // eslint-disable-next-line capitalized-comments -- v8 ignore
+  /* v8 ignore next 35 -- @preserve */
+  let dailyChallengesSpread: object = {};
+  // eslint-disable-next-line stylistic/max-len -- Long condition; splitting would reduce readability
+  if (incoming.dailyChallenges !== undefined && previous.dailyChallenges !== undefined) {
+    const previousChallengeMap = new Map(
+      previous.dailyChallenges.challenges.map((challenge) => {
+        return [ challenge.id, challenge ];
+      }),
+    );
+    // eslint-disable-next-line stylistic/max-len -- Long chain; splitting would reduce readability
+    const mergedChallenges = incoming.dailyChallenges.challenges.map((challenge) => {
+      const serverChallenge = previousChallengeMap.get(challenge.id);
+      if (serverChallenge === undefined) {
+        return challenge;
+      }
+      // eslint-disable-next-line stylistic/max-len -- Long expression; splitting would reduce readability
+      const bestProgress = Math.max(challenge.progress, serverChallenge.progress);
+      return {
+        ...challenge,
+        completed: bestProgress >= challenge.target,
+        progress:  bestProgress,
+      };
+    });
+    dailyChallengesSpread = {
+      dailyChallenges: {
+        ...incoming.dailyChallenges,
+        challenges: mergedChallenges,
+      },
+    };
+  } else if (previous.dailyChallenges !== undefined) {
+    dailyChallengesSpread = { dailyChallenges: previous.dailyChallenges };
+  }
+
   return {
     ...incoming,
     achievements,
@@ -693,6 +732,7 @@ const validateAndSanitize = (
     ...apotheosisSpread,
     ...explorationSpread,
     ...storySpread,
+    ...dailyChallengesSpread,
   };
 };
 
@@ -1024,7 +1064,8 @@ gameRouter.post("/save", async(context) => {
     const companionUnlocks = computeUnlockedCompanionIds({
       apotheosisCount:         stateToSave.apotheosis?.count ?? 0,
       lifetimeBossesDefeated:  playerRecord?.lifetimeBossesDefeated ?? 0,
-      lifetimeGoldEarned:      playerRecord?.lifetimeGoldEarned ?? 0,
+      // eslint-disable-next-line stylistic/max-len -- Long property; splitting would reduce readability
+      lifetimeGoldEarned:      (playerRecord?.lifetimeGoldEarned ?? 0) + stateToSave.player.totalGoldEarned,
       lifetimeQuestsCompleted: playerRecord?.lifetimeQuestsCompleted ?? 0,
       prestigeCount:           stateToSave.prestige.count,
       transcendenceCount:      stateToSave.transcendence?.count ?? 0,