refactor(marketing-pages)!: delete marketing-pages demo feature

Veect retrofit (ADR-027): fourth slice of the demo-content removal.
Deletes packages/marketing-pages whole and prunes every composition
edge in one commit: core-api router mount + dep, core-cms
collection/global composition + dep + regenerated Payload types,
web-next bindAll (prod + dev-seed) + tests + about page + Tailwind
source + transpilePackages + dep, cms/core-cms payload config test
assertions, marketing-page e2e spec, tsconfig paths, fallow ignore
entry, anchor-guard + generator e2e feature lists, compliance
data-map + retention-policy regeneration, lockfile prune, and
feature-list doc entries (CLAUDE.md, AGENTS.md, glossary, app/feature
AGENTS.md).

Event teardown: marketing-pages was the sole consumer of
auth.user.signed-up (welcome-email handler + job). The handler, its
Payload tasks, and the bus subscription all lived inside the package's
own binders, so they die with it — no other package wires the
subscription. Auth's manifest `publishes` stays untouched: a publisher
with zero consumers is legal (pnpm conformance only fails on orphan
consumers, verified green). The app-level sign-up-welcome-email test
asserted the marketing-pages mailer stays empty without a bus; it is
deleted with the feature, and the now-unused test-only bind-state
helpers in web-next bind-production.ts go with it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

packages/core-cms/src/payload.config.ts

@@ -5,7 +5,6 @@ import path from "node:path";
 import { fileURLToPath } from "node:url";
 
 import { users } from "@repo/auth/cms";
-import { pages, siteSettings } from "@repo/marketing-pages/cms";
 import { header } from "@repo/navigation/cms";
 
 const filename = fileURLToPath(import.meta.url);
@@ -13,8 +12,8 @@ const dirname = path.dirname(filename);
 
 export default buildConfig({
   editor: lexicalEditor(),
-  collections: [users, pages],
-  globals: [siteSettings, header],
+  collections: [users],
+  globals: [header],
   secret: process.env.PAYLOAD_SECRET || "default-secret-change-me",
   db: postgresAdapter({
     pool: {