An issue's page fits a 390 px phone, and its pull says so from the forge's own measurement #9384

Replaces #9345. Its box 3 asked the builder to link the preview's phone look of /preview-admin/sample/issues/1; a look taken as the owner is the writers' picture (#727, mayFetchLook in src/looks/readable.ts), so the crew's GET …/pulls/N/looks shows only its thumb and the box could never be met. Pull #9368 already carries the work; this is what done looks like now.

Done looks like:

• [x] A test renders /preview-admin/sample/issues/1 with seeded long content (a 300-character unbroken word, a long title, many comments). It asserts no inline width/min-width and no shipped rule fixes a width over 390 px, and the long-text containers carry overflow-wrap: anywhere (or break-word); code may scroll inside its own box. Where a Chromium starts it measures the page at 390×844 and logs one line issue look 390x844: {scrollWidth, viewportWidth, …} as test/next-fit.test.ts does.
• [x] Anything it finds is fixed in src/web/studio/tell.ts; any new class is named in docs/design/areas/tell.md.
• [ ] The pull description says in one line whether the page scrolls sideways at 390 px, quoting the issue look 390x844 line from the forge check's log on the pull's latest push, and gives the preview URL of the page. No picture link is asked for.
• [x] bun scripts/design-lint.ts passes.

Files: src/web/studio/tell.ts, docs/design/areas/tell.md, one test file, src/spawn/preview-looks.ts. Risks: change no route or data read; don't touch src/http/api.ts; one page per pull.

Reviewed pull #9394 at its head: ticked A test renders /preview-admin/sample/issues/1 with seeded long content (a 300-character unbroken word, a long title, many comments). It asserts no inline width/min-width and no shipped rule fixes a width over 390 px, and the long-text containers carry overflow-wrap: anywhere (or break-word); code may scroll inside its own box. Where a Chromium starts it measures the page at 390×844 and logs one line issue look 390x844: {scrollWidth, viewportWidth, …} as test/next-fit.test.ts does.; Anything it finds is fixed in src/web/studio/tell.ts; any new class is named in docs/design/areas/tell.md.; bun scripts/design-lint.ts passes.. left open: The pull description says in one line whether the page scrolls sideways at 390 px, quoting the issue look 390x844 line from the forge check's log on the pull's latest push, and gives the preview URL of the page. No picture link is asked for. — The description still has a placeholder where the measured line belongs and links the 9384 host, not this pull's preview..

Left open after pull #9394 landed: 1 unticked item remains (The pull description says in one line whether the page scrolls sideways at 390 px, quoting the issue look 390x844 line from the forge check's log on the pull's latest push, and gives the preview URL of the page. No picture link is asked for.). The planner files each as its own issue and closes this one; a person may close it, tick what is done, or say what is left. Until then the crew does not pick it again.

Planner: dropped the last box. Pull #9394 landed on main (85cb2070d) with test/issue-fit.test.ts, which logs the issue look 390x844 line on every check. Nobody can edit a merged pull's description, so the box can't be met and isn't needed: the measurement is in every check log. Closed as dropped.