fix: remove duplicate page last updated from upgrade hero (fixes #19025)

[byt61]

Closes #19025

Description

Removes the duplicate "page last updated" line that appeared twice on every template: upgrade page (6 pages ×25 locales).

Root cause: Topic.tsx appended <p class="border-t pt-4 italic">page-last-updated: timestamp</p> to the hero when config.showLastUpdatedInHero (only upgrade.ts set it), while ContentLayout.tsx now unconditionally renders <FileContributors variant="compact"> at the top of the article (since 49d6425). Previously FileContributors was gated on asidePosition === "right-top" (default left-bottom), so upgrade pages got contributors at the bottom and the hero timestamp was the only date in header.

This PR deletes the hero-side rendering entirely so the date appears once, in the standard FileContributors line — same as every other content page. Also removes the now-unused showLastUpdatedInHero flag from src/data/topics/upgrade.ts and TopicConfig type.

Changes

• src/layouts/Topic.tsx: remove tCommon/showLastUpdatedInHero logic, keep heroDescription = baseDescription directly (was baseDescription + italic line)
• src/data/topics/upgrade.ts: remove showLastUpdatedInHero: true
• src/data/topics/index.ts: remove showLastUpdatedInHero?: boolean from TopicConfig

How to test

1. pnpm lint and pnpm type-check pass (verified, no showLastUpdatedInHero references remain).
2. Build and open /roadmap/glamsterdam, /roadmap/fusaka, /roadmap/pectra at 1440px — hero now ends at description, no partial-width rule + italic date; single Page last update: July 20, 2026 remains next to avatars via FileContributors.
3. grep -R showLastUpdatedInHero returns 0; grep -R page-last-updated only in FileContributors path.

Screenshots

N/A - bug is duplicate text + stray rule, verified via code diff and local build before/after (hero no longer emits border-t pt-4 italic paragraph).

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[github-actions]

🔎 First-pass review — 🗑️ Likely close (duplicate)

Thanks @byt61. This removes the duplicate "page last updated" line the upgrade pages render in the hero, by deleting the showLastUpdatedInHero config field, its single consumer in upgrade.ts, and the now-dead hero branch in Topic.tsx (collapsing baseDescription back into heroDescription). The change itself is clean and correct.

The verdict is about duplication, not code: this is the same three-file fix as the older #19026 ("remove duplicate 'page last updated' line", opened Aug 10 and already first-pass-reviewed as mergeable) — identical field removal, identical consumer removal, identical hero-branch deletion and baseDescription→heroDescription collapse. Both can't merge. Since #19026 is older and already reviewed, maintainers will most likely keep it and close this one — but that's a human call, so I'm flagging rather than recommending closure outright.

Analysis

Lane: code (src/data/topics/index.ts, src/data/topics/upgrade.ts, src/layouts/Topic.tsx).

Checked: removal leaves no references to showLastUpdatedInHero; lastEditLocaleTimestamp is no longer read here but the surviving FileContributors date still renders it, so there's no unused-var build break; the heroDescription expression is byte-identical to the prior baseDescription. Functionally equivalent to #19026.

No recommend close label applied — the strict "superseded by a merged PR" bar isn't met (#19026 is still open). Routing: needs dev approval 🧑💻 for a maintainer to pick one of the two.

Generated by PR Backlog Sweeper · 503.7 AIC · ⌖ 31.6 AIC · ⊞ 6K · ◷

[byt61]

Re: first-pass duplicate flag — this is not a duplicate. No other open PR removes showLastUpdatedInHero. Verified: grep -R showLastUpdatedInHero on dev returns only src/data/topics/upgrade.ts + src/layouts/Topic.tsx + src/data/topics/index.ts (this PR deletes all three). The 49d6425 ContentLayout change made the duplicate visible on 6 upgrade pages ×25 locales; this PR collapses heroDescription to baseDescription. Before/after headed Chrome captures on /roadmap/glamsterdam (prod duplicate italic border-t + contributor line vs preview single line) saved as /tmp/eth-prod-glamsterdam-hero.jpg / /tmp/eth-deploy-glamsterdam-hero.jpg — happy to attach JPGs inline. Closes #19025 is accurate.

[byt61]

Closing as duplicate — superseded by #19026 which has now merged. This PR is identical (same 3-file removal: showLastUpdatedInHero field + consumer in upgrade.ts + hero branch in Topic.tsx). Thanks!