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

compliance/data-map.yml

@@ -2,10 +2,6 @@
 # Generated by scripts/compliance/emit-data-map.mjs — do not edit manually.
 # Run `pnpm compliance:data-map` to regenerate.
 collections:
-  articles:
-    auth: false
-    piiFields: []
-    slug: articles
   media:
     auth: false
     piiFields: []