feat: add verification method, categories, and dedup UI to control library

- Migration 047: verification_method + category columns, 17 category lookup table
- Backend: new filters, GET /categories, GET /controls/{id}/similar (embedding-based)
- Frontend: filter dropdowns, badges, dedup UI in ControlDetail with merge workflow
- ControlForm: verification method + category selects
- Provenance: verification methods, categories, master library strategy sections
- Fix UUID cast syntax in generator routes (::uuid -> CAST)

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

admin-compliance/app/sdk/control-library/components/ControlForm.tsx

@@ -2,7 +2,7 @@
 
 import { useState } from 'react'
 import { BookOpen, Trash2, Save, X } from 'lucide-react'
-import { EMPTY_CONTROL } from './helpers'
+import { EMPTY_CONTROL, VERIFICATION_METHODS, CATEGORY_OPTIONS } from './helpers'
 
 export function ControlForm({
   initial,
@@ -267,6 +267,37 @@ export function ControlForm({
           </select>
         </div>
       </div>
+
+      {/* Verification Method & Category */}
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="block text-xs font-medium text-gray-600 mb-1">Nachweismethode</label>
+          <select
+            value={form.verification_method || ''}
+            onChange={e => setForm({ ...form, verification_method: e.target.value || null })}
+            className="w-full px-3 py-2 text-sm border border-gray-300 rounded-lg"
+          >
+            <option value="">— Nicht zugewiesen —</option>
+            {Object.entries(VERIFICATION_METHODS).map(([k, v]) => (
+              <option key={k} value={k}>{v.label}</option>
+            ))}
+          </select>
+          <p className="text-xs text-gray-400 mt-1">Wie wird dieses Control nachgewiesen?</p>
+        </div>
+        <div>
+          <label className="block text-xs font-medium text-gray-600 mb-1">Kategorie</label>
+          <select
+            value={form.category || ''}
+            onChange={e => setForm({ ...form, category: e.target.value || null })}
+            className="w-full px-3 py-2 text-sm border border-gray-300 rounded-lg"
+          >
+            <option value="">— Nicht zugewiesen —</option>
+            {CATEGORY_OPTIONS.map(c => (
+              <option key={c.value} value={c.value}>{c.label}</option>
+            ))}
+          </select>
+        </div>
+      </div>
     </div>
   )
 }