Add Zod validation, fix mass assignment, remove test endpoints and dead code

- Add centralized Zod schemas (server/utils/schemas.js) and validateBody
  utility for all API endpoints
- Fix critical mass assignment in member creation: raw body no longer
  passed to new Member(), only validated fields (email, name, circle,
  contributionTier) are accepted
- Apply Zod validation to login, profile patch, event registration,
  updates, verify-payment, and admin event creation endpoints
- Fix logout cookie flags to match login (httpOnly: true, secure
  conditional on NODE_ENV)
- Delete unauthenticated test/debug endpoints (test-connection,
  test-subscription, test-bot)
- Remove sensitive console.log statements from Helcim and member
  endpoints
- Remove unused bcryptjs dependency
- Add 10MB file size limit on image uploads
- Use runtime config for JWT secret across all endpoints
- Add 38 validation tests (117 total, all passing)

server/api/admin/events.post.js

@@ -1,20 +1,14 @@
 import Event from "../../models/event.js";
 import { connectDB } from "../../utils/mongoose.js";
 import { requireAdmin } from "../../utils/auth.js";
+import { validateBody } from "../../utils/validateBody.js";
+import { adminEventCreateSchema } from "../../utils/schemas.js";
 
 export default defineEventHandler(async (event) => {
   try {
     const admin = await requireAdmin(event);
 
-    const body = await readBody(event);
-
-    // Validate required fields
-    if (!body.title || !body.description || !body.startDate || !body.endDate) {
-      throw createError({
-        statusCode: 400,
-        statusMessage: "Missing required fields",
-      });
-    }
+    const body = await validateBody(event, adminEventCreateSchema);
 
     await connectDB();