chore(spec): move the pointer-row pin to its own branch

The pin and its `vitest.repo-tests.json` declaration are a change to
`packages/spec/scripts/`, i.e. to the generator side of this repo. Carried here
they defeat the generated-artifact exception that would otherwise lift the
`skills/**` path on this PR: the recompute that certifies the regenerated index
would be running a tree that also modifies the generator it is trusting, so it
cannot certify itself.

What is left here is a pure `gen:skill-refs` / `gen:docs` regeneration beside
the one-line source fix. The pin lands separately and is not weakened.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016N6xmWt5hYm94ffVEwGH8x

Author: claude

packages/spec/scripts/solution-blueprint-header-row.test.ts

@@ -17,7 +17,6 @@
   "scripts/references-banner.test.ts",
   "scripts/root-index.test.ts",
   "scripts/schema-tree-freshness.test.ts",
-  "scripts/solution-blueprint-header-row.test.ts",
   "scripts/strictness-ledger-doc.test.ts",
   "scripts/strictness-ledger.test.ts",
   "src/api/error-catalog-docs.test.ts",