Promote AgentCompany-New to the repository root and retire the old app

The legacy application - its src, tests, landing site, promo assets, docs,
release tooling, CI workflows, and root configs - leaves the tree; it stays
reachable in history. Everything under AgentCompany-New moves up unchanged:
same package name, so the production userData/database path is untouched,
and e2e/build scripts already resolved paths relative to the project. The
developer cred.txt stays gitignored at its new location. Full verify:ci
passes from the new root.

tests/unit/cascade-safe-triangle.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, test } from "vitest";
+import { pointInTriangle } from "../../src/renderer/src/shared/CascadeMenu";
+
+// The safe triangle: apex at the cursor's prior position, base on the open
+// submenu's near (left) edge. A submenu sitting to the right spanning y∈[-20,40]
+// at x=100, with the cursor having just been at the origin.
+const apex = { x: 0, y: 0 };
+const top = { x: 100, y: -20 };
+const bottom = { x: 100, y: 40 };
+
+describe("safe triangle (cursor → submenu)", () => {
+  test("a cursor sweeping diagonally toward the submenu stays inside", () => {
+    // Midway to the submenu, within the widening cone — switching is deferred.
+    expect(pointInTriangle({ x: 50, y: 5 }, apex, top, bottom)).toBe(true);
+    expect(pointInTriangle({ x: 90, y: 30 }, apex, top, bottom)).toBe(true);
+  });
+
+  test("a cursor that drifts off-course toward a sibling row falls outside", () => {
+    // At x=50 the cone only spans y∈[-10,20]; y=30 is below it — let the sibling win.
+    expect(pointInTriangle({ x: 50, y: 30 }, apex, top, bottom)).toBe(false);
+    // Straight down from the apex, away from the submenu entirely.
+    expect(pointInTriangle({ x: 5, y: 35 }, apex, top, bottom)).toBe(false);
+  });
+
+  test("the apex and the submenu corners are on the triangle", () => {
+    expect(pointInTriangle(apex, apex, top, bottom)).toBe(true);
+    expect(pointInTriangle(top, apex, top, bottom)).toBe(true);
+    expect(pointInTriangle(bottom, apex, top, bottom)).toBe(true);
+  });
+});