A settings notice never draws as a red banner over a page: a test scans every page's first paint #10825

One sentence: the owner's rule 'a setting is one line where it belongs, never a banner over the board' becomes a failing test.

Done:

• [x] A test renders home, the board, /system and the apps list as the owner and asserts no element with the danger/alert class sits above the page's main content because of a setting (egress mode, limits, flags).
• [x] Any page the test catches moves its line to the setting's own page, with its reason beside it.
• [x] design-lint passes; before/after screenshots only if a page changed.

Files: src/web/pages/board.ts, home page, src/web/pages/admin-limits.ts as found, one new test. Risks: real failures (a red main, a down service) must still show; the test names the allowed kinds. Suits scout.

Reviewed pull #10832 at its head: ticked A test renders home, the board, /system and the apps list as the owner and asserts no element with the danger/alert class sits above the page's main content because of a setting (egress mode, limits, flags).; Any page the test catches moves its line to the setting's own page, with its reason beside it.; design-lint passes; before/after screenshots only if a page changed..