fix: patch adventurer stats on sync so rebalances apply to existing saves

Sync New Content now updates baseCost, class, combatPower, essencePerSecond,
goldPerSecond, level, and name for all existing adventurer entries to match
the current defaults, while preserving count and unlocked state.

Closes #126

apps/api/test/routes/debug.spec.ts

@@ -567,12 +567,44 @@ describe("debug route", () => {
       expect(res.status).toBe(404);
     });
 
-    it("returns 200 with zero counts when state already has all content", async () => {
+    it("returns 200 with zero added counts when state already has all content", async () => {
       const state = makeState();
       vi.mocked(prisma.gameState.findUnique).mockResolvedValueOnce({ state } as never);
       vi.mocked(prisma.gameState.update).mockResolvedValueOnce({} as never);
       const res = await syncNewContent();
       expect(res.status).toBe(200);
+      const body = await res.json() as { adventurerStatsPatched: number; bossRewardsPatched: number; questRewardsPatched: number };
+      expect(body.adventurerStatsPatched).toBe(0);
+      expect(body.bossRewardsPatched).toBe(0);
+      expect(body.questRewardsPatched).toBe(0);
+    });
+
+    it("patches adventurer stats when saved adventurer has outdated stats", async () => {
+      const state = makeState({
+        adventurers: [{ id: "militia", count: 5, unlocked: true, baseCost: 1, goldPerSecond: 1, essencePerSecond: 1, combatPower: 1, level: 1, name: "Old Name", class: "warrior" }] as GameState["adventurers"],
+      });
+      vi.mocked(prisma.gameState.findUnique).mockResolvedValueOnce({ state } as never);
+      vi.mocked(prisma.gameState.update).mockResolvedValueOnce({} as never);
+      const res = await syncNewContent();
+      expect(res.status).toBe(200);
+      const body = await res.json() as { adventurerStatsPatched: number; state: GameState };
+      expect(body.adventurerStatsPatched).toBe(1);
+      const adventurer = body.state.adventurers.find((a) => a.id === "militia");
+      expect(adventurer?.baseCost).not.toBe(1);
+      expect(adventurer?.count).toBe(5);
+      expect(adventurer?.unlocked).toBe(true);
+    });
+
+    it("skips adventurer stat patching for adventurers not in defaults", async () => {
+      const state = makeState({
+        adventurers: [{ id: "nonexistent_adventurer", count: 0, unlocked: false, baseCost: 1, goldPerSecond: 1, essencePerSecond: 1, combatPower: 1, level: 1, name: "Ghost", class: "warrior" }] as GameState["adventurers"],
+      });
+      vi.mocked(prisma.gameState.findUnique).mockResolvedValueOnce({ state } as never);
+      vi.mocked(prisma.gameState.update).mockResolvedValueOnce({} as never);
+      const res = await syncNewContent();
+      expect(res.status).toBe(200);
+      const body = await res.json() as { adventurerStatsPatched: number };
+      expect(body.adventurerStatsPatched).toBe(0);
     });
 
     it("injects missing entries when arrays are empty", async () => {