Wire view-mode toggles (alt-view + coordinate grid) via new ViewModeController

Moves the AlternateViewEvent / ToggleCoordinateGridEvent subscriptions out of
ClientGameRunner into a dedicated controller in src/client/controllers/. Also
wires ToggleCoordinateGridEvent (M keybind) — previously emitted with no
listener — so the persistent coordinate-grid toggle works. Grid + alt-view
hide names only under alt-view; M keeps names visible.

src/client/controllers/ViewModeController.ts

@@ -0,0 +1,29 @@
+/**
+ * ViewModeController — forwards map view-mode toggles to the WebGL view.
+ *
+ * - AlternateViewEvent: space-hold (and the settings-modal toggle) drives the
+ *   affiliation recolor + grid overlay + hides names.
+ * - ToggleCoordinateGridEvent: persistent coordinate-grid toggle (M keybind);
+ *   grid shows but names stay visible.
+ */
+
+import { EventBus } from "../../core/EventBus";
+import { Controller } from "../Controller";
+import { AlternateViewEvent, ToggleCoordinateGridEvent } from "../InputHandler";
+import { GameView as WebGLGameView } from "../render/gl";
+
+export class ViewModeController implements Controller {
+  constructor(
+    private eventBus: EventBus,
+    private view: WebGLGameView,
+  ) {}
+
+  init() {
+    this.eventBus.on(AlternateViewEvent, (e) =>
+      this.view.setAltView(e.alternateView),
+    );
+    this.eventBus.on(ToggleCoordinateGridEvent, (e) =>
+      this.view.setGridView(e.enabled),
+    );
+  }
+}