feat: blocklist table with registration check endpoint

- is_blocked BOOLEAN (default true), INET type for IP validation
- Indexes on email/username/phone/ip for fast registration checks
- POST /api/blocklist/check — checks all fields in one request, returns 403 if blocked
- Auto-timestamps on block/unblock, email stored lowercase

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/blocklist.js

@@ -0,0 +1,112 @@
+const router = require('express').Router();
+const { query } = require('../db');
+
+// GET /api/blocklist
+router.get('/', async (req, res, next) => {
+  try {
+    const { is_blocked, limit = 50, offset = 0 } = req.query;
+    const params = [Math.min(parseInt(limit), 500), parseInt(offset)];
+    const where = is_blocked !== undefined ? `WHERE is_blocked = $3` : '';
+    if (is_blocked !== undefined) params.push(is_blocked === 'true');
+    const result = await query(
+      `SELECT * FROM blocklist ${where} ORDER BY created_at DESC LIMIT $1 OFFSET $2`,
+      params
+    );
+    res.json(result.rows);
+  } catch (err) { next(err); }
+});
+
+// GET /api/blocklist/:id
+router.get('/:id', async (req, res, next) => {
+  try {
+    const result = await query('SELECT * FROM blocklist WHERE id = $1', [req.params.id]);
+    if (!result.rows.length) return res.status(404).json({ error: 'Not found' });
+    res.json(result.rows[0]);
+  } catch (err) { next(err); }
+});
+
+// POST /api/blocklist/check — Registrierungs-Check
+router.post('/check', async (req, res, next) => {
+  try {
+    const { username, email, phone, ip } = req.body;
+    if (!username && !email && !phone && !ip)
+      return res.status(400).json({ error: 'Provide at least one field to check' });
+
+    const conditions = [];
+    const params = [];
+    if (email)    { params.push(email.toLowerCase());  conditions.push(`lower(email) = $${params.length}`); }
+    if (username) { params.push(username.toLowerCase()); conditions.push(`lower(username) = $${params.length}`); }
+    if (phone)    { params.push(phone);                conditions.push(`phone = $${params.length}`); }
+    if (ip)       { params.push(ip);                   conditions.push(`ip = $${params.length}`); }
+
+    const result = await query(
+      `SELECT id, is_blocked, username, email, phone, ip FROM blocklist
+       WHERE is_blocked = true AND (${conditions.join(' OR ')})
+       LIMIT 1`,
+      params
+    );
+
+    if (result.rows.length) {
+      return res.status(403).json({ blocked: true, matched: result.rows[0] });
+    }
+    res.json({ blocked: false });
+  } catch (err) { next(err); }
+});
+
+// POST /api/blocklist — Eintrag anlegen
+router.post('/', async (req, res, next) => {
+  try {
+    const { username, email, phone, ip } = req.body;
+    if (!username && !email && !phone && !ip)
+      return res.status(400).json({ error: 'Provide at least one of: username, email, phone, ip' });
+
+    const result = await query(
+      `INSERT INTO blocklist (username, email, phone, ip, blocked_at)
+       VALUES ($1, $2, $3, $4, NOW()) RETURNING *`,
+      [username || null, email ? email.toLowerCase() : null, phone || null, ip || null]
+    );
+    res.status(201).json(result.rows[0]);
+  } catch (err) { next(err); }
+});
+
+// PATCH /api/blocklist/:id — blockieren / entsperren
+router.patch('/:id', async (req, res, next) => {
+  try {
+    const allowed = ['is_blocked', 'username', 'email', 'phone', 'ip', 'blocked_at', 'unblocked_at'];
+    const fields = Object.keys(req.body).filter(k => allowed.includes(k));
+    if (!fields.length) return res.status(400).json({ error: 'No valid fields provided' });
+
+    // Auto-timestamps bei is_blocked Wechsel
+    if (req.body.is_blocked === true && !req.body.blocked_at) {
+      fields.push('blocked_at');
+      req.body.blocked_at = new Date().toISOString();
+    }
+    if (req.body.is_blocked === false && !req.body.unblocked_at) {
+      fields.push('unblocked_at');
+      req.body.unblocked_at = new Date().toISOString();
+    }
+
+    // Email normalisieren
+    if (req.body.email) req.body.email = req.body.email.toLowerCase();
+
+    const setClauses = fields.map((f, i) => `${f} = $${i + 1}`).join(', ');
+    const values = [...fields.map(f => req.body[f]), req.params.id];
+    const result = await query(
+      `UPDATE blocklist SET ${setClauses} WHERE id = $${fields.length + 1} RETURNING *`,
+      values
+    );
+    if (!result.rows.length) return res.status(404).json({ error: 'Not found' });
+    res.json(result.rows[0]);
+  } catch (err) { next(err); }
+});
+
+// DELETE /api/blocklist/:id
+router.delete('/:id', async (req, res, next) => {
+  try {
+    const result = await query('DELETE FROM blocklist WHERE id = $1 RETURNING id', [req.params.id]);
+    if (!result.rows.length) return res.status(404).json({ error: 'Not found' });
+    res.status(204).end();
+  } catch (err) { next(err); }
+});
+
+module.exports = router;