feat: alle lizenzen auflisten - GET /api/v1/licenses (+ ?email= filter)

- Neuer admin-endpunkt GET /api/v1/licenses listet alle lizenzen inkl. email,
  status, max_activations, activations_used, produkt, daten.
- Optionaler ?email=<adresse> filter (case-insensitive) fuer eine kundenmail.
- Integrationstest-abdeckung ergaenzt.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

license-backend/src/server.js

@@ -126,6 +126,23 @@ const Q = {
     'INSERT INTO products (slug, name, created_at) VALUES (?, ?, ?)'
   ),
   licenseByKey: db.prepare('SELECT * FROM licenses WHERE key = ?'),
+  allLicenses: db.prepare(`
+    SELECT l.key, l.status, l.max_activations, l.email, l.note,
+           l.created_at, l.expires_at, p.slug AS product,
+           (SELECT COUNT(*) FROM activations a WHERE a.license_id = l.id) AS activations_used
+    FROM licenses l
+    JOIN products p ON p.id = l.product_id
+    ORDER BY l.created_at DESC
+  `),
+  licensesByEmail: db.prepare(`
+    SELECT l.key, l.status, l.max_activations, l.email, l.note,
+           l.created_at, l.expires_at, p.slug AS product,
+           (SELECT COUNT(*) FROM activations a WHERE a.license_id = l.id) AS activations_used
+    FROM licenses l
+    JOIN products p ON p.id = l.product_id
+    WHERE l.email = ? COLLATE NOCASE
+    ORDER BY l.created_at DESC
+  `),
   insertLicense: db.prepare(`
     INSERT INTO licenses (key, product_id, max_activations, status, email, note, created_at, expires_at)
     VALUES (@key, @product_id, @max_activations, 'active', @email, @note, @created_at, @expires_at)
@@ -657,6 +674,14 @@ app.post('/api/v1/licenses', adminOnly, (req, res) => {
   });
 });
 
+// List all licenses (each row includes its email). Optional ?email=… filters to
+// one customer's licenses (case-insensitive exact match).
+app.get('/api/v1/licenses', adminOnly, (req, res) => {
+  const email = req.query.email ? String(req.query.email).trim() : '';
+  const rows = email ? Q.licensesByEmail.all(email) : Q.allLicenses.all();
+  return res.json({ ok: true, count: rows.length, licenses: rows });
+});
+
 // Inspect a license (status + bound domains).
 app.get('/api/v1/licenses/:key', adminOnly, (req, res) => {
   const license = Q.licenseByKey.get(req.params.key);