{# Compound-report shell.
Context vars (assembled by fs_report.compound_assembler):
- ``compound`` — the CompoundRecipe being rendered.
- ``cover_html`` — pre-rendered cover-page HTML (or empty string).
- ``toc_entries`` — list[{anchor, title, number}] for the TOC.
- ``show_toc`` — bool; gates the TOC block.
- ``show_page_numbers`` — bool; gates the page-number footer.
- ``compound_libs`` — deduped list of chart-library tokens (echarts,
marked, dompurify, chartjs, datalabels) drawn
from each child's Recipe.chart_libraries.
- ``section_blocks`` — list[str]; one HTML block per child (already
contains the section divider + fragment body OR
a failure-callout placeholder).
- ``classification`` — text for cover badge + page footer (may be empty).
- ``tokens_inline_css`` — verbatim contents of static/css/tokens.css.
The compound shell is the home for compound-wide CSS (cover, page
layout, section dividers). Per-section CSS travels INSIDE each
section block — fragment_extractor scopes it to ``.fs-section-