feat(fork)!: remove all frontend Enterprise-Edition code (community build)

Strip the proprietary client EE so the fork ships a clean community/AGPL
edition, mirroring Forkmost. Delete apps/client/src/ee (201 files) and
packages/ee, and patch every consumer that imported from @/ee/*.

- gate-out EE features (useHasFeature -> false): API keys, SSO, MFA, SCIM,
  audit logs, AI / AI-chat, templates, page permissions, page verification,
  comment resolution, trash retention, viewer comments
- drop cloud/billing/trial/entitlement/posthog flows; sign-in is now
  email+password only (no SSO/LDAP/cloud)
- remove EE routes from App.tsx and EE entries from sidebars/settings nav
- restore the community page-share button (ShareModal) that the EE
  PageShareModal used to provide
- remove the dead "Attachments" search filter, dead MFA navigation and
  orphaned route constants

Client type-checks clean; full `pnpm build` is green for all three projects.

apps/client/src/features/editor/page-editor.tsx

@@ -70,7 +70,6 @@ import { PageEditMode } from "@/features/user/types/user.types.ts";
 import { jwtDecode } from "jwt-decode";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { useEditorScroll } from "./hooks/use-editor-scroll";
-import { EditorAiMenu } from "@/ee/ai/components/editor/ai-menu/ai-menu";
 import { EditorLinkMenu } from "@/features/editor/components/link/link-menu";
 import ColumnsMenu from "@/features/editor/components/columns/columns-menu.tsx";
 import { TransclusionLookupProvider } from "@/features/editor/components/transclusion/transclusion-lookup-context";
@@ -431,7 +430,6 @@ export default function PageEditor({
 
             {editor && editorIsEditable && (
               <div>
-                <EditorAiMenu editor={editor} />
                 <EditorLinkMenu editor={editor} />
                 <EditorBubbleMenu editor={editor} />
                 <TableMenu editor={editor} />