feat: another balance and bug fix pass (#238)

Working through open issues — fixes, balance changes, and features.

## Closed

- Closes #161
- Closes #181
- Closes #191
- Closes #199
- Closes #201
- Closes #202
- Closes #203
- Closes #204
- Closes #205
- Closes #206
- Closes #208
- Closes #211
- Closes #212
- Closes #213
- Closes #214
- Closes #216
- Closes #219
- Closes #220
- Closes #221
- Closes #222
- Closes #224
- Closes #225
- Closes #226
- Closes #228
- Closes #229
- Closes #230
- Closes #231
- Closes #232
- Closes #233
- Closes #234
- Closes #235
- Closes #236

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #238
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/api/src/routes/game.ts

@@ -546,6 +546,17 @@ const validateAndSanitize = (
       ? previous.prestige
       : incoming.prestige;
 
+  /*
+   * If the DB prestige count is higher than the client's, the client is sending a
+   * stale pre-prestige save. Discard its upgrades (which have purchased: true) in
+   * favour of the DB's post-prestige upgrades (purchased: false) so that upgrade
+   * multipliers cannot persist across prestige via a race-condition auto-save.
+   */
+  const upgrades
+    = incoming.prestige.count < previous.prestige.count
+      ? previous.upgrades
+      : incoming.upgrades;
+
   /*
    * Echoes are only granted server-side via transcendence and can only decrease between
    * saves (spent on echo upgrades). Cap at the previous value to block inflation.
@@ -611,11 +622,17 @@ const validateAndSanitize = (
         = Math.min(material.quantity, previousQuantity);
       return { ...material, quantity: cappedQuantity };
     });
-    const craftedRecipeIds = incoming.exploration.craftedRecipeIds.filter(
-      (recipeId) => {
-        return previousExploration.craftedRecipeIds.includes(recipeId);
-      },
-    );
+
+    /*
+     * Merge crafted recipe IDs from both states so the list can only ever grow.
+     * A stale auto-save arriving after a craft must not silently un-craft items.
+     */
+    const craftedRecipeIds = [
+      ...new Set([
+        ...previousExploration.craftedRecipeIds,
+        ...incoming.exploration.craftedRecipeIds,
+      ]),
+    ];
     explorationSpread = {
       exploration: {
         ...incoming.exploration,
@@ -671,6 +688,7 @@ const validateAndSanitize = (
     prestige,
     quests,
     resources,
+    upgrades,
     ...transcendenceSpread,
     ...apotheosisSpread,
     ...explorationSpread,