feat(postgres): migrate all route files from SQLite to pg pool

- All 16 route files now import pool from ../db directly
- Removed db parameter from all factory functions
- All callbacks replaced with async/await pool.query()
- All ? placeholders converted to $1, $2... numbered params
- datetime('now') → NOW(), INSERT OR IGNORE → ON CONFLICT DO NOTHING
- LIKE → ILIKE for case-insensitive searches
- Error detection: err.code === '23505' for unique violations
- server.js no longer passes pool/db/requireAuth to route factories
- Only ivantiFindings.js still receives pool (pending task 8 rewrite)

backend/routes/nvdLookup.js

@@ -1,13 +1,14 @@
 // NVD CVE Lookup Routes
 const express = require('express');
+const { requireAuth } = require('../middleware/auth');
 
 const CVE_ID_PATTERN = /^CVE-\d{4}-\d{4,}$/;
 
-function createNvdLookupRouter(db, requireAuth) {
+function createNvdLookupRouter() {
     const router = express.Router();
 
     // All routes require authentication
-    router.use(requireAuth(db));
+    router.use(requireAuth());
 
     // Lookup CVE details from NVD API 2.0
     router.get('/lookup/:cveId', async (req, res) => {