The search page's live line draws §5's .small row and link, and .live-toggle leaves its markup #4401

Replaces #4195. The only use is one paragraph at src/web/pages/search.ts:431 (<p class="live-toggle small"> with an icon and a link). No test pins the class. One earlier try failed only on the load-sensitive Files page timing test ("the Files page's cold first view of a fresh head"), which this change does not touch.

Done:

• [ ] That paragraph is drawn with §5's components and classes (for example row with .small, .muted and §5's link style). Name which in the pull. live-toggle does not appear in the search page's HTML. Its icon and link text are unchanged, and the link points where it does today.
• [ ] Do not delete the rules in src/web/style/content.ts and do not edit docs/DESIGN.md; #4196 does that.
• [ ] A test in the search page's test file asserts that live-toggle is absent and that the link and its words are present.
• [ ] bun x tsc --noEmit, bun scripts/design-lint.ts and bun test test/design-lint.test.ts plus the search tests pass. If only test/pull-timing.test.ts fails, name it in the pull as unrelated rather than editing it.