fix(www): break long URLs in tutorial prose, and widen the sideways-scroll guard

[choraria]

Follow-up to #857, found by extending that PR's mobile sweep across every marketing route at 320 / 360 / 375 / 393px.

The defect

Three provider pages dragged the whole document sideways on a narrow phone:

Page	Document width	Viewport
/test/calendly	381px	360px
/test/github	372px	360px
/test/notion	345px	320px

Tutorial prose is authored per provider in lib/tutorials.ts and routinely carries a bare URL — "POST to https://api.calendly.com/webhook_subscriptions with url, events…". Under the default overflow-wrap: normal a URL is one unbreakable token: it doesn't wrap, it runs past the paragraph, and the document widens with it. The terminal blocks on these pages are correctly overflow-x-auto and scroll inside their own box; the paragraphs had nothing.

Why nothing caught it

no page scrolls sideways on a phone already existed — and reported green on every run. It ran at exactly one viewport, the mobile project's Pixel 5 default of 393px, which all three pages happen to fit.

A viewport-sensitive assertion pinned to a single viewport is not a guard against layout; it is a guard against one phone. This is the same shape as the bug in #857, where the check was blind because the hero section is overflow-hidden.

The guard now runs at 320 / 360 / 393px — 111 checks instead of 37. Before this fix it is red on all three pages (5 failures: three at 320px, two at 360px) and still green at 393px — the blindness demonstrated, not asserted.

The fix

break-words on the shared body prose class.

• Not break-all. overflow-wrap: break-word breaks a long token only when it cannot fit a line of its own, so ordinary sentences still wrap at their spaces.
• The event-name chips in the same file already carry break-words, with a comment giving the same reasoning. This is that idiom, applied to the prose.
• The "Worth knowing first" paragraph spelled the same class string out by hand instead of using body, so it would have been left behind. It now uses the constant — hand-copying a shared class string is exactly how one of two identical paragraphs ends up without the fix.

Test plan

• Playwright mobile — 191 passed (was 117; +74 from the widened guard)
• Playwright chromium — 138 passed
• apps/www vitest — 562 passed
• pnpm lint (eslint + all repo guards, incl. content-dup-guard over the 16 sibling tutorial pages) ✓ · typecheck ✓ · format:check ✓
• test:seo ✓ · test:anchors ✓ · test:orphans ✓ · test:links ✓ · check:export ✓

Human verification

Lower risk than #857 — this is a wrapping rule on body copy, no layout or control moved. Worth a glance at /test/calendly on a phone to confirm the long URL now wraps mid-token rather than running off, and that surrounding sentences still break at spaces.

🤖 Generated with Claude Code

https://claude.ai/code/session_012gEktpYFKUo4FweY9BeuzU