Fix: enrich non-EN Kaikki search results with translations from EN hub

When searching for DE/FR/ES/etc. words, the Kaikki entries have empty
translations. Now does a reverse lookup to find the EN entry and copies
its 24-language translations. This ensures wordInNative() works for
all languages, not just the original 7.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-lehrer/vocabulary/api.py

@@ -82,13 +82,38 @@ async def _search_kaikki(q: str, lang: str, limit: int, offset: int):
         if isinstance(tr, str):
             import json as _json
             tr = _json.loads(tr)
+
+        en_word = ""
+        en_ipa = ""
+
+        if r["lang"] == "en":
+            en_word = r["word"]
+            en_ipa = r["ipa"] or ""
+        else:
+            # Non-EN entries have empty translations — enrich from EN via reverse lookup
+            if not tr or len(tr) < 3:
+                async with pool.acquire() as conn2:
+                    en_row = await conn2.fetchrow(
+                        """SELECT word, ipa, translations FROM vocabulary_kaikki
+                           WHERE lang = 'en' AND translations->'%s'->>'text' ILIKE $1
+                           ORDER BY length(word) LIMIT 1""" % lang,
+                        r["word"],
+                    )
+                    if en_row:
+                        en_word = en_row["word"]
+                        en_ipa = en_row["ipa"] or ""
+                        en_tr = en_row["translations"]
+                        if isinstance(en_tr, str):
+                            en_tr = _json.loads(en_tr)
+                        tr = en_tr
+
         words.append({
             "id": str(r["id"]),
-            "english": r["word"] if r["lang"] == "en" else "",
-            "german": tr.get("de", {}).get("text", "") if r["lang"] == "en" else r["word"] if r["lang"] == "de" else "",
+            "english": en_word if r["lang"] != "en" else r["word"],
+            "german": tr.get("de", {}).get("text", "") if r["lang"] != "de" else r["word"],
             "word": r["word"],
             "lang": r["lang"],
-            "ipa_en": r["ipa"] if r["lang"] == "en" else "",
+            "ipa_en": en_ipa if r["lang"] != "en" else (r["ipa"] or ""),
             "ipa_de": r["ipa"] if r["lang"] == "de" else "",
             "part_of_speech": r["pos"],
             "syllables_en": [],