chore(api): upgrade zod to v4 with v3 compat layer (GRO-131)

- Bump zod from ^3.24.1 to ^4.3.6
- Bump @hono/zod-validator from ^0.4.3 to ^0.7.6
- Update all 12 route files to import from "zod/v3" compat layer

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/routes/book.ts

@@ -1,6 +1,6 @@
 import { Hono } from "hono";
 import { zValidator } from "@hono/zod-validator";
-import { z } from "zod";
+import { z } from "zod/v3";
 import {
   and,
   eq,