feat(npcs): free rotate overlays and drop session zoom tools

Drag the top-edge handle to rotate the whole frame with the avatar; remove unused zoom controls from the session NPC window.

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

app/main/npcs/npcsOverlayStore.ts

@@ -107,7 +107,10 @@ export class NpcsOverlayStore {
           focusNpcId: event.npcId,
           layouts: {
             ...this.state.layouts,
-            [event.npcId]: clampNpcsLayout(event.layout),
+            [event.npcId]: clampNpcsLayout({
+              ...layoutFor(this.state, event.npcId),
+              ...event.layout,
+            }),
           },
         };
         return this.state;