chore: more feedback fixes (#129)

## Summary

- Fix `NaN` displayed in Sync New Content / Force Unlock notifications by guarding against undefined counts
- Poll server for exploration claimability before showing Collect button to prevent client/server desync
- Return authoritative materials list from craft API to prevent client desync causing false affordability
- Add test coverage for `sync-new-content` and `explore/claimable` endpoints

Closes #125
Closes #127
Closes #128

## Test plan

- [ ] Trigger a sync with new content and verify the notification shows a real count instead of `NaN`
- [ ] Start an exploration, wait for it to complete, and verify the Collect button only appears after the server confirms claimable
- [ ] Attempt to craft a recipe and verify the material counts in the UI update to match the server's authoritative values

✨ This issue was created with help from Hikari~ 🌸

Reviewed-on: #129
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/api/src/routes/craft.ts

@@ -148,11 +148,22 @@ craftRouter.post("/", async(context) => {
 
     const bonusType = recipe.bonus.type;
     const bonusValue = recipe.bonus.value;
+    const { materials } = state.exploration;
+    const {
+      craftedGoldMultiplier,
+      craftedEssenceMultiplier,
+      craftedClickMultiplier,
+      craftedCombatMultiplier,
+    } = updatedMultipliers;
     const response: CraftRecipeResponse = {
       bonusType,
       bonusValue,
+      craftedClickMultiplier,
+      craftedCombatMultiplier,
+      craftedEssenceMultiplier,
+      craftedGoldMultiplier,
+      materials,
       recipeId,
-      ...updatedMultipliers,
     };
     return context.json(response);
   } catch (error) {