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-eslint/anchors.test.js

@@ -5,7 +5,7 @@ import { fileURLToPath } from "node:url";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const REPO_ROOT = join(__dirname, "..", "..");
-const FEATURES = ["auth", "marketing-pages", "navigation"];
+const FEATURES = ["auth", "navigation"];
 const ANCHORS = {
   "src/index.ts": ["// <gen:events>", "// <gen:realtime-channels>"],
   "src/di/symbols.ts": [