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.

landing/components/theme-toggle.tsx

@@ -1,42 +0,0 @@
-"use client";
-
-import { useTheme } from "./theme-provider";
-
-function SunIcon() {
-  return (
-    <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
-      <circle cx="12" cy="12" r="5" />
-      <line x1="12" y1="1" x2="12" y2="3" />
-      <line x1="12" y1="21" x2="12" y2="23" />
-      <line x1="4.22" y1="4.22" x2="5.64" y2="5.64" />
-      <line x1="18.36" y1="18.36" x2="19.78" y2="19.78" />
-      <line x1="1" y1="12" x2="3" y2="12" />
-      <line x1="21" y1="12" x2="23" y2="12" />
-      <line x1="4.22" y1="19.78" x2="5.64" y2="18.36" />
-      <line x1="18.36" y1="5.64" x2="19.78" y2="4.22" />
-    </svg>
-  );
-}
-
-function MoonIcon() {
-  return (
-    <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
-      <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z" />
-    </svg>
-  );
-}
-
-export function ThemeToggle() {
-  const { theme, toggleTheme } = useTheme();
-
-  return (
-    <button
-      type="button"
-      onClick={toggleTheme}
-      aria-label={`Switch to ${theme === "light" ? "dark" : "light"} mode`}
-      className="relative inline-flex items-center justify-center w-11 h-11 rounded-lg transition-colors duration-200 cursor-pointer hover:bg-[var(--panel-soft)] text-[var(--muted)] hover:text-[var(--text)]"
-    >
-      {theme === "light" ? <MoonIcon /> : <SunIcon />}
-    </button>
-  );
-}