Confirm the banner renders as a callout (spec 011, Task 3.5)

[iancooper]

Closes the last leftover from Spec 011's requirements Q1: does the page banner actually
render as a callout below the title, or does GitBook emit it literally?

It needed a published branch, and #74 supplied one by merging — so this was checked
against the live site rather than a preview revision. Documentation only; no page
under contents/ is touched.

What was checked

GitBook emits <h1> … </header>, then the banner as the first element of the content
body:

<blockquote class="… border-l-2 pl-6 py-3 border-tint …">
  <strong>Explanation</strong> · Applies to <strong>Brighter V10</strong> ·
  Prerequisites: <a href="…/guaranteed-at-least-once/rabbitmqconfiguration">RabbitMQ Configuration</a>

A real blockquote with a left border and padding — a callout below the title, which is
what the convention asks for. **Reference** becomes <strong>, the · separators
survive as U+00B7, and the Prerequisites link is a genuine anchor (fetched: 200).

12 pages sampled across the corpus, including all five that carry a Prerequisites
segment. That half of the banner grammar had never appeared in a rendered page until
the Phase 6 splits created pages using it, so this is the first time it has been
checkable at all.

The check that would have proved nothing

The first attempt read the page through a Markdown-converting fetcher, which returned:

> **Explanation** · Applies to **Brighter V10** · Prerequisites: [RabbitMQ Configuration](…)

That is exactly what a correctly rendered blockquote converts back to — and equally
what an unrendered literal banner would look like. The two are indistinguishable
after conversion, and GitBook rendering such things literally is precisely the concern
behind Q1. The check had to be run against raw HTML for the <blockquote> element, and
was.

Also settled

The published site is 111 URLs (sitemap-pages.xml) — 110 pages plus the index — so
all five pages created by the Phase 6 splits are live, and none is orphaned in the
published tree.

Verification

python3 tools/linkcheck.py     # No broken internal links (112 files checked)
python3 tools/pagelint.py      # 0 errors, 836 warnings across 110 pages

Spec 011 is now 40 of 43 tasks. Remaining: the language-tag backfill, --fix for
pagelint.py, and the acceptance pass.

🤖 Generated with Claude Code

https://claude.ai/code/session_012tcdwxVb8NmKaX2S6fvyFg