feat: Scanned-Keys 'Alle prüfen' Button + EasyMDE Refresh nach More-Toggle

- POST /api/admin/api-keys/scanned/recheck-all: prüft alle nicht-adoptierten Scanned-Keys sequenziell
- Button mit Loading-State, Ergebnis-Toast und Auto-Reload
- EasyMDE/CodeMirror refresh() nach initMoreButton() Einblenden (behebt leeren Editor-Bug)

Endpoints/ApiKeysEndpoint.cs

@@ -29,6 +29,7 @@ public static class ApiKeysEndpoint
         app.MapPost("/api/admin/api-keys/scan", HandleScanTrigger);
         app.MapGet("/api/admin/api-keys/scan/status", HandleScanStatus);
         app.MapGet("/api/admin/api-keys/scanned", HandleGetScanned);
+        app.MapPost("/api/admin/api-keys/scanned/recheck-all", HandleRecheckAll);
         app.MapPost("/api/admin/api-keys/scanned/{id}/recheck", HandleRecheck);
         app.MapPost("/api/admin/api-keys/scanned/{id}/adopt", HandleAdopt);
         app.MapDelete("/api/admin/api-keys/scanned/{id}", HandleDeleteScanned);
@@ -274,6 +275,27 @@ public static class ApiKeysEndpoint
         await ctx.Response.WriteAsJsonAsync(result);
     }
 
+    private static async Task HandleRecheckAll(HttpContext ctx, DatabaseService db, KeyScannerService scanner)
+    {
+        if (!ctx.IsAdmin()) { ctx.Response.StatusCode = 403; return; }
+
+        var keys = await db.GetScannedKeys();
+        var notAdopted = keys.Where(k => k.AdoptedApiKeyId == null).ToList();
+
+        int success = 0, errors = 0;
+        foreach (var sk in notAdopted)
+        {
+            try
+            {
+                await scanner.CheckAndUpdateKey(sk);
+                success++;
+            }
+            catch { errors++; }
+        }
+
+        await ctx.Response.WriteAsJsonAsync(new { ok = true, total = notAdopted.Count, success, errors });
+    }
+
     private static async Task HandleRecheck(HttpContext ctx, DatabaseService db, KeyScannerService scanner, string id)
     {
         if (!ctx.IsAdmin()) { ctx.Response.StatusCode = 403; return; }