Add semantic badges

[MaggieAppleton]

Summary

• add a static semantic Badge primitive composed from IconLabel
• preserve visible text and decorative-icon accessibility across four tones
• add compact pill styling and four-tone design-audit coverage
• tune badge padding to 4/10/4/8 px, icon to 16 px, and icon–text gap to 4 px

Scope

Badge only. Motion/state APIs, callouts, metric deltas, tooltips, and product adoption remain separate.

Stack

• depends on Add accessible progress bars #174

Verification

• badge update: 6 focused tests pass; browser confirms selected dimensions
• focused tests: 41 pass
• bun test: 1,502 pass, 2 PostgreSQL skips, 0 fail
• bun run types
• bun run ci
• bun run build
• git diff --check

Component preview