docs(knowledge): clarify KB improvement front door

[drewstone]

Summary

• add a README contents list and the runKnowledgeImprovementJob front door
• show a concrete KB improvement snippet with budget and backend
• add the KB job to the main runtime use-case table and examples list
• remove em dashes from the runtime README touched surface and fix the examples count to 29

Verification

• pnpm run docs:check passed
• rg -n "—" README.md returned no matches
• README quality scan: em_dash=0 hype_hits=0 headings=10 code_blocks=6
• git merge-tree --write-tree origin/main HEAD returned cdbf2c3cd280664df0fc0c16da73cc8363bbbdec

[tangletools]

✅ Auto-approved drewstone PR — 15a894fe

This PR was opened by the trusted drewstone account.
The full PR reviewer audit still runs separately and will publish findings if it detects issues.

_{tangletools · auto-approval · reason: drewstone_author · 2026-07-08T20:16:35Z}