Add relation manager: link/unlink records directly in modal

- RelationManager component: shows linked items as removable tags,
  live search to find and add new links (×-button to unlink)
- tables.js: full fetchRelated config with linkEndpoint + searchEndpoint
  for words↔pictures, words↔categories, objects↔words, objects↔pictures
- api.js: add apiLink, apiUnlink, apiDelete helpers

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

src/components/RecordModal.jsx

@@ -1,5 +1,5 @@
 import { useEffect, useState, useCallback } from 'react';
-import { apiPatch, apiFetchOne } from '../lib/api';
+import { apiPatch, apiFetchOne, apiFetch, apiLink, apiUnlink } from '../lib/api';
 import { STATUS_COLORS } from '../lib/tables';
 
 const READ_ONLY_FIELDS = new Set(['id', 'created_at', 'updated_at']);
@@ -104,12 +104,143 @@ function EditableField({ fieldKey, value, fieldDef, onChange }) {
   );
 }
 
+function RelationManager({ recordId, rel }) {
+  const [items, setItems] = useState(undefined);   // undefined = loading
+  const [search, setSearch] = useState('');
+  const [searchResults, setSearchResults] = useState(null);
+  const [searching, setSearching] = useState(false);
+  const [showSearch, setShowSearch] = useState(false);
+  const [error, setError] = useState('');
+
+  // Load linked items
+  useEffect(() => {
+    setItems(undefined);
+    apiFetchOne(rel.endpoint(recordId))
+      .then(data => setItems(Array.isArray(data) ? data : []))
+      .catch(() => setItems(null));
+  }, [recordId, rel]);
+
+  // Search available items
+  useEffect(() => {
+    if (!showSearch) return;
+    if (!search.trim()) { setSearchResults([]); return; }
+    const timer = setTimeout(() => {
+      setSearching(true);
+      apiFetch(`${rel.searchEndpoint}?limit=20&offset=0`)
+        .then(data => {
+          const arr = Array.isArray(data) ? data : [];
+          const q = search.toLowerCase();
+          const linked = new Set((items || []).map(i => i.id));
+          setSearchResults(
+            arr.filter(r => rel.searchLabel(r).toLowerCase().includes(q) && !linked.has(r.id))
+          );
+        })
+        .catch(() => setSearchResults([]))
+        .finally(() => setSearching(false));
+    }, 250);
+    return () => clearTimeout(timer);
+  }, [search, showSearch, items, rel]);
+
+  async function handleLink(targetId) {
+    try {
+      await apiLink(rel.linkEndpoint(recordId, targetId));
+      // refresh
+      const data = await apiFetchOne(rel.endpoint(recordId));
+      setItems(Array.isArray(data) ? data : []);
+      setSearch('');
+      setSearchResults([]);
+      setShowSearch(false);
+    } catch (e) { setError(e.message); }
+  }
+
+  async function handleUnlink(targetId) {
+    try {
+      await apiUnlink(rel.linkEndpoint(recordId, targetId));
+      setItems(prev => (prev || []).filter(i => i.id !== targetId));
+    } catch (e) { setError(e.message); }
+  }
+
+  return (
+    <section>
+      <div className="flex items-center justify-between mb-2">
+        <h3 className="text-xs font-bold text-slate-400 uppercase tracking-widest">{rel.label}</h3>
+        <button
+          onClick={() => { setShowSearch(s => !s); setSearch(''); setSearchResults([]); }}
+          className="text-xs text-indigo-600 hover:text-indigo-800 font-medium flex items-center gap-1"
+        >
+          {showSearch ? '✕ Schließen' : '+ Verknüpfen'}
+        </button>
+      </div>
+
+      {/* Search box */}
+      {showSearch && (
+        <div className="mb-2">
+          <input
+            autoFocus
+            type="text"
+            placeholder={`${rel.label} suchen…`}
+            value={search}
+            onChange={e => setSearch(e.target.value)}
+            className="w-full border border-slate-300 rounded-lg px-3 py-1.5 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-400"
+          />
+          {searching && <p className="text-xs text-slate-400 mt-1">Suche…</p>}
+          {searchResults && searchResults.length === 0 && search && !searching && (
+            <p className="text-xs text-slate-400 mt-1">Keine Ergebnisse</p>
+          )}
+          {searchResults && searchResults.length > 0 && (
+            <div className="mt-1 border border-slate-200 rounded-lg overflow-hidden max-h-36 overflow-y-auto">
+              {searchResults.map(r => (
+                <button
+                  key={r.id}
+                  onClick={() => handleLink(r.id)}
+                  className="w-full text-left px-3 py-1.5 text-sm hover:bg-indigo-50 hover:text-indigo-700 transition-colors border-b border-slate-100 last:border-0"
+                >
+                  {rel.searchLabel(r)}
+                </button>
+              ))}
+            </div>
+          )}
+        </div>
+      )}
+
+      {/* Linked items */}
+      <div className="bg-slate-50 rounded-lg p-3 min-h-[40px]">
+        {items === undefined && (
+          <div className="flex gap-1">
+            {[1,2,3].map(i => <div key={i} className="h-6 w-16 bg-slate-200 rounded animate-pulse" />)}
+          </div>
+        )}
+        {items === null && <span className="text-xs text-red-500">Fehler beim Laden</span>}
+        {Array.isArray(items) && items.length === 0 && (
+          <span className="text-sm text-slate-400">Keine verknüpften Einträge</span>
+        )}
+        {Array.isArray(items) && items.length > 0 && (
+          <div className="flex flex-wrap gap-1.5">
+            {items.map(item => (
+              <span key={item.id} className="group flex items-center gap-1 text-xs bg-indigo-50 text-indigo-700 rounded-full pl-2.5 pr-1 py-1 font-medium">
+                {rel.display(item)}
+                <button
+                  onClick={() => handleUnlink(item.id)}
+                  className="text-indigo-400 hover:text-red-500 hover:bg-red-50 rounded-full w-4 h-4 flex items-center justify-center transition-colors"
+                  title="Verknüpfung entfernen"
+                >
+                  ×
+                </button>
+              </span>
+            ))}
+          </div>
+        )}
+        {error && <p className="text-xs text-red-500 mt-1">{error}</p>}
+      </div>
+    </section>
+  );
+}
+
 export default function RecordModal({ record, meta, onClose, onSaved }) {
   const [values, setValues] = useState({});
   const [dirty, setDirty] = useState({});
   const [saving, setSaving] = useState(false);
   const [saveError, setSaveError] = useState('');
-  const [related, setRelated] = useState({});
 
   // Init values from record
   useEffect(() => {
@@ -117,22 +248,8 @@ export default function RecordModal({ record, meta, onClose, onSaved }) {
     setValues({ ...record });
     setDirty({});
     setSaveError('');
-    setRelated({});
   }, [record]);
 
-  // Fetch related data (e.g. pictures → words)
-  useEffect(() => {
-    if (!record || !meta.fetchRelated?.length) return;
-    meta.fetchRelated.forEach(rel => {
-      apiFetchOne(rel.endpoint(record.id))
-        .then(data => {
-          const arr = Array.isArray(data) ? data : [];
-          setRelated(prev => ({ ...prev, [rel.key]: arr }));
-        })
-        .catch(() => setRelated(prev => ({ ...prev, [rel.key]: null })));
-    });
-  }, [record, meta]);
-
   const handleChange = useCallback((key, val) => {
     setValues(prev => ({ ...prev, [key]: val }));
     setDirty(prev => ({ ...prev, [key]: true }));
@@ -249,37 +366,9 @@ export default function RecordModal({ record, meta, onClose, onSaved }) {
             </section>
           )}
 
-          {/* Related data (fetched separately) */}
+          {/* Related data with link/unlink */}
           {meta.fetchRelated?.map(rel => (
-            <section key={rel.key}>
-              <h3 className="text-xs font-bold text-slate-400 uppercase tracking-widest mb-3">
-                {rel.label}
-              </h3>
-              <div className="bg-slate-50 rounded-lg p-3">
-                {related[rel.key] === undefined && (
-                  <div className="flex gap-1">
-                    {[1,2,3].map(i => (
-                      <div key={i} className="h-6 w-16 bg-slate-200 rounded animate-pulse" />
-                    ))}
-                  </div>
-                )}
-                {related[rel.key] === null && (
-                  <span className="text-xs text-red-500">Fehler beim Laden</span>
-                )}
-                {Array.isArray(related[rel.key]) && related[rel.key].length === 0 && (
-                  <span className="text-sm text-slate-400">Keine Einträge</span>
-                )}
-                {Array.isArray(related[rel.key]) && related[rel.key].length > 0 && (
-                  <div className="flex flex-wrap gap-1.5">
-                    {related[rel.key].map((item, i) => (
-                      <span key={item.id || i} className="text-xs bg-indigo-50 text-indigo-700 rounded-full px-2.5 py-1 font-medium">
-                        {rel.display(item)}
-                      </span>
-                    ))}
-                  </div>
-                )}
-              </div>
-            </section>
+            <RelationManager key={rel.key} recordId={record.id} rel={rel} />
           ))}
 
           {/* Read-only metadata */}