feat(control): grid snap, NPC context actions, and overlay dim fix

Re-enable users-branch UI, snap session tokens to square/hex grid from the control preview, refine inactive/open-info NPC menus, block marker actions while an effect brush is active, and dim materials/NPC overlays only when they are open.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/shared/sceneOverlay/sceneOverlayHost.test.ts

@@ -18,6 +18,9 @@ void test('SceneOverlayHost: один dim для materials + npcs в Control и
 
   assert.ok(host.includes('styles.dim'));
   assert.ok(host.includes('hostHitThrough'));
+  // Dim только при active; жёлтая рамка без затемнения.
+  assert.match(host, /\{active \? <div className=\{styles\.dim\}/);
+  assert.ok(host.includes('showViewportGuide'));
   assert.ok(control.includes('SceneOverlayHost'));
   assert.ok(control.includes('embedded'));
   assert.ok(presentation.includes('SceneOverlayHost'));
@@ -29,6 +32,7 @@ void test('SceneOverlayHost: один dim для materials + npcs в Control и
   assert.ok(control.includes('embedded'));
   assert.ok(presentation.includes('embedded'));
   assert.match(css, /\.hostHitThrough\s*\{[^}]*pointer-events:\s*none/s);
+  assert.match(css, /\.dim\s*\{[^}]*inset:\s*0/s);
 });
 
 void test('MaterialOverlay / NpcsSceneOverlay поддерживают embedded без собственного dim', () => {