feat(setup): /api/setup-words-pictures – M2M-Relation words↔pictures einrichten

Einmaliger Setup-Endpoint: setzt special=m2m auf Alias-Felder,
erstellt Relations für words_pictures Junction in Directus.

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

app.py

@@ -1575,6 +1575,64 @@ def setup_directus_schema():
                     "failed": len(failed), "results": results})
 
 
+@app.route("/api/setup-words-pictures", methods=["POST"])
+def setup_words_pictures():
+    """
+    Einmalig ausführen: Konfiguriert die M2M-Relation words ↔ pictures
+    via words_pictures Junction in Directus.
+    Idempotent – bereits vorhandene Felder/Relationen werden übersprungen.
+    """
+    token = request.headers.get("Authorization", "")
+    results = []
+
+    def do(label, method, path, body=None):
+        data, status = _directus(method, path, token, body)
+        ok = status in (200, 201, 204)
+        results.append({"label": label, "status": status, "ok": ok,
+                         "err": None if ok else (data.get("errors") or data)})
+        return ok
+
+    # Sicherstellen dass Junction-Collection existiert
+    _ensure_junction("words_pictures", "words_id", "pictures_id", token)
+
+    # special=m2m auf Alias-Felder setzen (idempotent)
+    do("patch pictures.linked_words special", "PATCH", "/fields/pictures/linked_words", {
+        "type": "alias",
+        "meta": {"special": ["m2m"], "interface": "list-m2m",
+                 "options": {"template": "{{words_id.title_de}}"},
+                 "note": "Verknüpfte Safe Words"},
+    })
+    do("patch words.linked_pictures special", "PATCH", "/fields/words/linked_pictures", {
+        "type": "alias",
+        "meta": {"special": ["m2m"], "interface": "list-m2m",
+                 "options": {"template": "{{pictures_id.media}}"},
+                 "note": "Verknüpfte Bilder"},
+    })
+
+    # Relation words_pictures.words_id → words
+    do("relation words_pictures.words_id→words", "POST", "/relations", {
+        "collection": "words_pictures", "field": "words_id",
+        "related_collection": "words",
+        "schema": {"on_delete": "CASCADE"},
+        "meta": {"junction_field": "pictures_id",
+                 "one_field": "linked_pictures",
+                 "one_deselect_action": "nullify"},
+    })
+    # Relation words_pictures.pictures_id → pictures
+    do("relation words_pictures.pictures_id→pictures", "POST", "/relations", {
+        "collection": "words_pictures", "field": "pictures_id",
+        "related_collection": "pictures",
+        "schema": {"on_delete": "CASCADE"},
+        "meta": {"junction_field": "words_id",
+                 "one_field": "linked_words",
+                 "one_deselect_action": "nullify"},
+    })
+
+    failed = [r for r in results if not r["ok"]]
+    return jsonify({"ok": len(failed) == 0, "total": len(results),
+                    "failed": len(failed), "results": results})
+
+
 if __name__ == "__main__":
     app.run(host="0.0.0.0", port=8000, debug=True)