refactor(blog)!: delete blog demo feature

Veect retrofit (ADR-027): the template's demo content is being removed
to make room for the Veect package map. This slice deletes
packages/blog whole and prunes every composition edge in one commit:
core-api router mount, core-cms collections + regenerated Payload
types, web-next bindAll entry / home page / blog route / Tailwind
sources, blog e2e spec, tsconfig paths, fallow ignore entry,
anchor-guard + generator e2e feature lists, compliance artifacts,
and feature-list doc entries (CLAUDE.md, AGENTS.md, glossary).

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

packages/core-cms/package.json

@@ -17,7 +17,6 @@
     "@payloadcms/db-postgres": "^3.14.0",
     "@payloadcms/richtext-lexical": "^3.14.0",
     "@repo/auth": "workspace:*",
-    "@repo/blog": "workspace:*",
     "@repo/marketing-pages": "workspace:*",
     "@repo/media": "workspace:*",
     "@repo/navigation": "workspace:*",