fix: reimport dict-cursor bug + add admin cleanup endpoint

Problem 1: Reimport fails completely (all exercises fail)
Root cause: Line 465 existing[0] instead of existing['id']
Fix: Changed to existing['id'] for dict-cursor compatibility

Problem 2: 221 exercises skipped, only 2 in database
Root cause: Orphaned wiki_import_references from failed imports
Fix: New admin endpoint to manually cleanup orphaned references

New endpoints:
- DELETE /api/import/mediawiki/admin/cleanup-orphaned-references
  Deletes all references where local_id doesn't exist in target table
  Returns count of deleted references per type

- GET /api/import/mediawiki/admin/stats
  Shows references vs. actual count + orphaned count
  Helps diagnose import state issues

Usage:
1. Call cleanup endpoint to remove orphaned references
2. Run normal import (reimport=false)
3. Should import all previously failed exercises

backend/main.py

@@ -70,7 +70,7 @@ def read_root():
     }
 
 # Register routers
-from routers import auth, profiles, exercises, clubs, skills, training_planning, catalogs, import_wiki
+from routers import auth, profiles, exercises, clubs, skills, training_planning, catalogs, import_wiki, import_wiki_admin
 
 app.include_router(auth.router)
 app.include_router(profiles.router)
@@ -80,6 +80,7 @@ app.include_router(skills.router)
 app.include_router(training_planning.router)
 app.include_router(catalogs.router)
 app.include_router(import_wiki.router)
+app.include_router(import_wiki_admin.router)
 
 if __name__ == "__main__":
     import uvicorn

backend/routers/import_wiki.py

@@ -462,7 +462,7 @@ def _upsert_exercise(mapped: dict, reimport: bool) -> Optional[int]:
         equipment = _json.dumps(mapped.get("equipment", [])) if mapped.get("equipment") else None
 
         if existing and reimport:
-            ex_id = existing[0]
+            ex_id = existing['id']
             cur.execute(
                 """UPDATE exercises SET
                     title = %s, summary = %s, goal = %s, execution = %s,

backend/routers/import_wiki_admin.py

@@ -0,0 +1,95 @@
+"""
+Admin-Hilfsfunktionen für MediaWiki-Import
+"""
+from fastapi import APIRouter, Depends, HTTPException
+from db import get_db, get_cursor
+from routers.import_wiki import require_admin
+
+router = APIRouter(prefix="/api/import/mediawiki/admin", tags=["import-admin"])
+
+
+@router.delete("/cleanup-orphaned-references")
+def cleanup_orphaned_references(session: dict = Depends(require_admin)):
+    """
+    Löscht verwaiste Import-Referenzen (Referenz existiert, aber Übung fehlt).
+    Nützlich nach fehlgeschlagenen Imports.
+    """
+    deleted = {"exercises": 0, "skills": 0, "methods": 0}
+
+    with get_db() as conn:
+        cur = get_cursor(conn)
+
+        # Exercises
+        cur.execute("""
+            DELETE FROM wiki_import_references
+            WHERE content_type = 'exercise'
+            AND local_id NOT IN (SELECT id FROM exercises)
+        """)
+        deleted["exercises"] = cur.rowcount
+
+        # Skills
+        cur.execute("""
+            DELETE FROM wiki_import_references
+            WHERE content_type = 'skill'
+            AND local_id NOT IN (SELECT id FROM skills)
+        """)
+        deleted["skills"] = cur.rowcount
+
+        # Methods
+        cur.execute("""
+            DELETE FROM wiki_import_references
+            WHERE content_type = 'method'
+            AND local_id NOT IN (SELECT id FROM training_methods)
+        """)
+        deleted["methods"] = cur.rowcount
+
+        conn.commit()
+
+    return {
+        "ok": True,
+        "deleted": deleted,
+        "message": f"Deleted {sum(deleted.values())} orphaned references"
+    }
+
+
+@router.get("/stats")
+def get_import_stats(session: dict = Depends(require_admin)):
+    """Statistik über Import-Referenzen vs. tatsächliche Einträge."""
+    with get_db() as conn:
+        cur = get_cursor(conn)
+
+        # Exercises
+        cur.execute("SELECT COUNT(*) as count FROM wiki_import_references WHERE content_type = 'exercise'")
+        refs_exercises = cur.fetchone()['count']
+        cur.execute("SELECT COUNT(*) as count FROM exercises WHERE import_source = 'mediawiki'")
+        actual_exercises = cur.fetchone()['count']
+
+        # Skills
+        cur.execute("SELECT COUNT(*) as count FROM wiki_import_references WHERE content_type = 'skill'")
+        refs_skills = cur.fetchone()['count']
+        cur.execute("SELECT COUNT(*) as count FROM skills")
+        actual_skills = cur.fetchone()['count']
+
+        # Methods
+        cur.execute("SELECT COUNT(*) as count FROM wiki_import_references WHERE content_type = 'method'")
+        refs_methods = cur.fetchone()['count']
+        cur.execute("SELECT COUNT(*) as count FROM training_methods")
+        actual_methods = cur.fetchone()['count']
+
+    return {
+        "exercises": {
+            "references": refs_exercises,
+            "actual": actual_exercises,
+            "orphaned": refs_exercises - actual_exercises
+        },
+        "skills": {
+            "references": refs_skills,
+            "actual": actual_skills,
+            "orphaned": refs_skills - actual_skills
+        },
+        "methods": {
+            "references": refs_methods,
+            "actual": actual_methods,
+            "orphaned": refs_methods - actual_methods
+        }
+    }