[information-architecture] Homepage reviewer guide links to missing workflow pages

## Information Architecture Findings

### 1. Homepage discovery path leads to dead-end reviewer links
**Area:** Navigation
**Component(s):** `docs/index.md`, `docs/blog/posts/meet-the-reviewers.md`
**Problem:** The homepage routes users to the “Meet the Reviewers” guide, but that guide links to multiple workflow docs that do not exist. Users following this top-level path hit dead ends and cannot continue to setup details from the reviewer overview.
**Suggested improvement:** Replace dead links with existing workflow docs (or add the missing docs pages), then add a docs link-check in CI for blog/workflow cross-links so this path stays navigable.

**Evidence:**
- `docs/index.md:126` links from homepage card to `blog/posts/meet-the-reviewers.md`.
- `docs/blog/posts/meet-the-reviewers.md:25` links to `../../workflows/gh-agent-workflows/pr-review-addresser.md` (missing file).
- `docs/blog/posts/meet-the-reviewers.md:39` links to `../../workflows/gh-agent-workflows/update-pr-body.md` (missing file).
- `docs/blog/posts/meet-the-reviewers.md:45` links to `../../workflows/gh-agent-workflows/estc-docs-pr-review.md` (missing file).

## Suggested Actions
- [ ] Update `meet-the-reviewers.md` to point only to existing reviewer workflow pages, or add the missing pages.
- [ ] Add docs link validation for blog-to-workflow links in CI to prevent future dead-end navigation regressions.

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