# [FEAT] Report section-manifest model and resolver - #78

Summary

First step of the report section-numbering refactor: a data-driven section manifest so headings, numbers, inclusion, and jump-nav stop being hand-typed and inconsistent across report pages. This PR is infrastructure only — the model and resolver plus unit tests. No page generator is wired to it yet, so no rendered output changes and there is no golden re-baseline. The grid pilot that consumes it follows on a later branch.

What's here

oceanarray/reports/_manifest.py (package-neutral — it names no variable, page, or science — so it is vendored byte-identical to the sister repos):

• Panel / Section / Expand / Profile dataclasses describing a page as an ordered list of sections, each naming panel ids that render figures or tables.
• Panel.kind ("figure" / "html" / "table") — a discriminator so the eventual render macro applies |safe only to markup panels and never to a base64 figure payload, keeping the autoescape=True boundary to one branch.
• Panel.slot accepts a str or a ctx -> str callable, so a page that derives a panel's width from its aspect ratio can compute the slot at resolution time; the resolver calls it when callable.
• resolve(profile, ctx, panels) — one pass: splice Expand entries, drop sections whose applies_to is false (collected into a not-applicable list), resolve each kept section's panels (a None render becomes a .warn stub; a kept section whose panels all return None keeps its heading with one stub), then number the survivors — content sections 1..N, appendix sections A... Numbering is compact (over the rendered subset), so an absent section leaves no gap; identity is the section id (a stable slug), not the integer.

tests/unit/test_manifest.py — 18 tests covering flat/none numbering, appendix lettering rollover, Expand splicing, applies_to dropping to the not-applicable list, None-render stubs, the kept-but-empty case, silent panel omission, kind carry-through, and callable-slot resolution.

Why compact numbering

A gap (1, 2, 4) reads as a rendering bug. Reserved numbering does not deliver stability either — inserting one section renumbers every downstream heading on every page and breaks every golden — whereas compaction leaves a page unchanged when a section it never had is added elsewhere. Cross-page comparability comes from the profile fixing the order (hydrography always before velocity) and from stable anchors, not from the integers.

Tests

18 new unit tests, all passing; full suite green; ruff clean. No existing code touched, so nothing else moves.