Phone tab bar in icon themes (Direct work, 2026-11-02)

Problem: On a 375px phone with six tabs (signed-in: Board, Recent, Users, Messages, New post, You), the Word 97, Chicago and Midnight tab bar overflowed. Each 16px nav icon sat beside its label in a 56px tab, so the Users icon landed on "Messages", "Messages" was clipped and "New post" wrapped. Light and other text-only themes fit at the same width. Reported from an iPhone running Firefox.

Reuse decision: The icons come from the shared sheet public/assets/theme-nav-icons.css (keyed to nav hrefs; loaded for every theme, rules scoped to the three icon themes). The base phone tab bar lives in public/assets/site.css under @media (max-width: 639px). The overflow is caused only by the icon sheet, so the fix is one phone-width block appended to that sheet: tab items become a column (icon above label), label at 0.7rem, icon margin reset, "New post" kept on one line. No markup change (templates/partials/app_header.php, templates/partials/nav.php untouched), no per-theme duplication.

Verification (Chrome, prod HTML with the local icon sheet substituted):

• iPhone 8 viewport, six tabs: zero horizontal overflow in Word 97, Chicago, Midnight; light unchanged. Screenshots reviewed for all three icon themes.

• 1280px desktop: tab widths identical before and after (media query only).

• tests/browser/nav_active_theme_styles.mjs passes (16 themes).

• tests/browser/tab_bar_scroll.mjs passes (phone hide/show, desktop unchanged).

• ./v3 test Word97ThemeCoverageTest passes.

• Not verified on a physical iPhone / WebKit; no WebKit build available locally.

Follow-ups noticed, not changed:

• Desktop: the Recent icon has no right margin and touches its label (theme-nav-icons.css, [href="/recent/"]::before lacks margin-right).

• FORUM_APP_VERSION_NOTIFICATION is off on prod because /api/version returns the content repository's git head, which changes with every post. Tracking the code checkout's head instead would make the reload banner fire only on deploys.