Phase 6 (Stufe 6): MongoDB vollstaendig entfernt

- Legacy-Form stillgelegt: frm_main(.Designer/.resx) + frm_analytics(.Designer/.resx)
  geloescht, 'Open Legacy'-Menue aus LauncherForm entfernt.
- Program.cs: IMongoDatabase-Registrierung + closed_trades-Cleanup weg;
  Trade-Nummerierung liest jetzt hoechste TradeId aus ICopyTradeLogRepository.
- StartupHydrationService: Mongo-/Bson-Fallback entfernt (Settings kommen aus
  dem Repo; fehlende Accounts erhalten Default-Settings).
- Alle Mongo*Repository (Core 4 + Modul 4) geloescht; DI-Zweige auf EF/MySQL
  reduziert (AddCorePersistence, CopyTradingModule).
- ConfigMigrator: Mongo-Pfad (Run/MigrateSettings) entfernt; nur noch
  RunFromJson + VerifyMySql (kein Mongo-Treiber mehr).
- Modelle: [BsonId] entfernt (EF-Keys via HasKey); ObjectId-Defaults -> Guid.
- LiteDB-Shim (MongoDbLiteDBShim) geloescht; MongoDB.Driver- + LiteDB-Pakete
  aus App/Core entfernt; stale usings + user-sichtbare Strings bereinigt.
- DatabaseOptions/appsettings.json: Mongo-Provider/Connection-Felder entfernt.
- Build gruen; --verify-mysql bestaetigt 3 Accounts/3 Settings/32 Trader/2344 Markets.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Ui/LauncherForm.Designer.cs

@@ -19,7 +19,6 @@ namespace PolyTraderSharp.Ui
         {
             menuStrip = new MenuStrip();
             miDatei = new ToolStripMenuItem();
-            miLegacy = new ToolStripMenuItem();
             miBeenden = new ToolStripMenuItem();
             toolstrip_windows = new ToolStrip();
             btn_dashboard = new ToolStripButton();
@@ -51,17 +50,11 @@ namespace PolyTraderSharp.Ui
             // 
             // miDatei
             // 
-            miDatei.DropDownItems.AddRange(new ToolStripItem[] { miLegacy, miBeenden });
+            miDatei.DropDownItems.AddRange(new ToolStripItem[] { miBeenden });
             miDatei.Name = "miDatei";
             miDatei.Size = new Size(69, 29);
             miDatei.Text = "Datei";
-            // 
-            // miLegacy
-            // 
-            miLegacy.Name = "miLegacy";
-            miLegacy.Size = new Size(275, 34);
-            miLegacy.Text = "Legacy-UI (alte Tabs)";
-            // 
+            //
             // miBeenden
             // 
             miBeenden.Name = "miBeenden";
@@ -202,7 +195,6 @@ namespace PolyTraderSharp.Ui
 
         private System.Windows.Forms.MenuStrip menuStrip;
         private System.Windows.Forms.ToolStripMenuItem miDatei;
-        private System.Windows.Forms.ToolStripMenuItem miLegacy;
         private System.Windows.Forms.ToolStripMenuItem miBeenden;
         private ToolStrip toolstrip_windows;
         private ToolStripButton btn_settings;

Ui/LauncherForm.cs

@@ -21,7 +21,6 @@ namespace PolyTraderSharp.Ui
         private readonly TradingState _state;
         private readonly System.Windows.Forms.Timer _statusTimer = new() { Interval = 1000 };
         private readonly Dictionary<string, ToolStripButton> _viewButtons;
-        private frm_main? _legacyForm;
 
         public LauncherForm(ShellUiHost uiHost, IServiceProvider services)
         {
@@ -47,7 +46,6 @@ namespace PolyTraderSharp.Ui
 
             btn_liveTrading.Click += (_, _) => CycleLiveTrading();
             btn_demoTrading.Click += (_, _) => CycleDemoTrading();
-            miLegacy.Click += (_, _) => OpenLegacy();
             miBeenden.Click += (_, _) => Close();
 
             // Offen-Status der Fenster spiegeln (Button „checked", wenn Fenster offen).
@@ -126,25 +124,8 @@ namespace PolyTraderSharp.Ui
 
             lbl_ratelimit.Text = $"API: {(_state.IsAlchemyHealthy ? "WSS aktiv" : "Polling")}";
 
-            // Toggle-Buttons mit externem State synchron halten (z.B. Änderungen aus der Legacy-UI).
             UpdateTradingToggles();
             UpdateWindowButtonStates();
         }
-
-        private void OpenLegacy()
-        {
-            if (_legacyForm != null && !_legacyForm.IsDisposed)
-            {
-                if (_legacyForm.WindowState == FormWindowState.Minimized)
-                    _legacyForm.WindowState = FormWindowState.Normal;
-                _legacyForm.BringToFront();
-                _legacyForm.Activate();
-                return;
-            }
-
-            _legacyForm = _services.GetRequiredService<frm_main>();
-            _legacyForm.FormClosed += (_, _) => _legacyForm = null;
-            _legacyForm.Show();
-        }
     }
 }