The settings and origins pages' numbered steps draw §5's stack and muted text, and .steps leaves the markup #4302

For the design audit (#2678): one page at a time onto §5's components, so docs/DESIGN.md §5d only shrinks. Part one of two: this part changes only the markup; the stylesheet and docs/DESIGN.md are part two.

Done:

• [ ] The numbered how-to lists (<ol class="steps"> in src/web/pages/settings.ts and the two in src/web/pages/origins.ts) are drawn with §5's stack and muted text, or a small ui.ts helper that both call (name which in the pull). They stay ordered lists, still numbered. None of .steps appears in either page's HTML.
• [ ] Do not delete the rules from src/web/style/content.ts and do not edit docs/DESIGN.md: part two does that.
• [ ] Every step's words and links are still there; a test asserts steps is absent and the list and its items are present on both pages.

Files: src/web/pages/settings.ts, src/web/pages/origins.ts, a test. Before pushing, run bun x tsc --noEmit, bun test test/design-lint.test.ts, bun scripts/design-lint.ts and both pages' tests. No screenshots: the sandbox has no browser.