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

apps/web-next/e2e/blog-post.spec.ts

@@ -1,20 +0,0 @@
-import { test, expect } from "@playwright/test";
-
-test("/blog/[slug] returns 404 for non-existent slug", async ({ page }) => {
-  const response = await page.goto("/blog/this-slug-does-not-exist", {
-    waitUntil: "domcontentloaded",
-  });
-  expect(response?.status()).toBe(404);
-});
-
-test("/blog/[slug] for a real slug renders the article", async ({ page }) => {
-  // The mock blog repository is empty by default — so this test currently
-  // expects 404. When seeded data exists in Payload, replace 404 with 200
-  // and check for article.title in the page body.
-  test.skip(
-    true,
-    "Pending: seed a published article in Payload before enabling this test",
-  );
-  await page.goto("/blog/example-slug");
-  await expect(page.locator("h1").first()).toBeVisible();
-});