Add author and translator attribution per lecture page

[mmcky]

Part of QuantEcon/project-themes#3 (author and translator attribution across all themes).

What

The theme currently has no per-page author attribution and no translator concept. Add rendering for both authors and translators — each a list of {name, url} pairs — so lecture pages credit their authors and, for translated editions (zh-cn, fa, fr), the translators who produced them.

Scope for this repo

• Read authors and translators from the MyST project configuration (myst.yml site/project options) as the project-level default, and from page front matter as a per-page override. Reuse the existing MyST authors front-matter convention where it fits rather than inventing a parallel key.
• Render both under the page title, with translators visually distinguished from authors (distinct class, rel="author" only on authors).
• Make the "Authors" / "Translators" labels overridable so each edition can render them in its own language.
• Omit the translators block entirely when the list is empty.

Design decisions

The data model, placement, and label-localisation decisions are being settled in the tracking issue QuantEcon/project-themes#3 so all three themes stay consistent — implement against whatever is agreed there. This also relates to the book-theme parity work in QuantEcon/meta#93 and the internationalisation phase in QuantEcon/meta#90.

Acceptance

• A project with authors and translators configured shows both on every page; a project with neither renders exactly as today.
• A page-level override replaces the project-level value for that page only.

[mmcky]

Rescoped 2026-09-04: translators only

Two changes from the theme-estate review on QuantEcon/workspace-themes#1.

This issue is now on the parity gate. #147 has moved it out of Not in scope and into the work plan — the ground it was excluded on ("beyond the book-theme feature set") stopped being true on 2026-08-25, when quantecon-book-theme v0.22.0 shipped translators, the day before that exclusion was written. The reasoning is in the scope-change note on #147.

The opening claim is wrong and the scope narrows. This issue says "The theme currently has no per-page author attribution and no translator concept." The authors half is not true: the theme has rendered per-page authors since d1ac95aa (2025-02-14). app/components/PageContent.tsx:52-55 passes authors={article.frontmatter.authors} into app/components/ProjectFrontmatter.tsx, which renders each as a linked Author component with comma and "and" joining, and the block is snapshot-tested through tests/visual/fixture/features.md. PLAN.md:57 lists "author header" under Already at parity, ticked on both stacks.

What actually remains

• The translators block, rendered under the page title and visually distinguished from the authors line (distinct class; rel="author" on authors only).
• The per-page override — project-level default from myst.yml, overridable in page front matter.
• A localisable label, so each edition renders "Translators" in its own language. This overlaps Phase 4 i18n (Phase 4 — Internationalisation (language switcher + hreflang) #90), which is on the gate for the same translated-series reason; build the label mechanism once across the two.
• Omit the block entirely when the list is empty.

The placement question stays open and is a real design decision rather than a port — the two themes' header structures are inverses. While designing it, note QuantEcon/quantecon-book-theme#432: on the Sphinx side the credit is rendered into the landing page and then hidden by display: none on .main-index, and page-header.js recovers only the authors, so a translated edition's front door currently credits nobody. Worth not reproducing that shape.

The body edits are folded into #160, which already proposes corrections to this issue.

[mmcky]

Built as #174, with Phases 4–5, on the shape settled on QuantEcon/workspace-themes#3.

• translators (list of {name, url?}) and translators_label (default "Translated by") under site.options; per-page override under site: in page frontmatter with replace-never-merge semantics, an explicit empty value suppressing the credit, and an unreadable value leaving the site-wide credit in place. Mirrors the book theme's _resolve_people rules.
• Placement, the question left open above: at the end of the "Last changed" row, as book-theme v0.22.0 does, because this theme's authors and last-changed control already share one row and a stacked fourth line read as clutter there too. Distinct class qe-page__header-translators, no rel="author" on the links. The landing page credits translators as well, so the front door does not take the quantecon-book-theme#432 shape.
• The label is the localisation mechanism (translators_label, plus language_switcher_label for the switcher); the list connector stays English, the gap the book theme records.
• Written as a YAML block string because template options are scalar-only (Every undeclared site.options key is dropped by the CLI, so twitter and launch_* never reach the theme #173); the theme also accepts a real list.

Closes when #174 merges.

[mmcky]

Shipped in #174, released in v2.6.0 (2026-09-10)

Delivered, on the shape settled on QuantEcon/workspace-themes#3. translators (a list of name and optional url) and translators_label (default "Translated by") under site.options; a per-page override under site: in page frontmatter that replaces rather than merges, an explicitly empty value suppressing the credit on that page, and an unreadable value leaving the site-wide credit in place, mirroring the book theme's resolution rules. Rendered at the end of the "Last changed" row as book-theme v0.22.0 places it, with the distinct class qe-page__header-translators and no rel="author" on the links; the landing page credits translators too.

Acceptance. A project with neither option renders exactly as before: asserted on the single-edition fixture and confirmed on the v2.6.0 build of lecture-python-programming#363, which sets neither. The page-level override and the suppression are covered by the visual suite.

Authors were already at parity (per the 2026-09-04 rescope), so that half needed no work. Two gaps stay recorded rather than built: rel="author" on author links belongs to upstream's Author component, and the list connector stays English, the same gap the book theme records.