docs(readme): clarify knowledge usage paths

[drewstone]

Summary

• add a Common Uses table for wiki, RAG, memory DB, from-scratch KBs, existing KBs, parallel agents, and the runtime one-call job
• add the runKnowledgeImprovementJob runtime integration example with budget and backend
• remove em dashes and hype phrasing from the README touched surface

Verification

• pnpm install --frozen-lockfile completed
• pnpm run lint passed: 89 files checked
• rg -n "—" README.md returned no matches
• README quality scan: em_dash=0 hype_hits=0 headings=14 code_blocks=17
• git merge-tree --write-tree origin/main HEAD returned ade298b608c58e75c7ca32eb669bfba5452d3590

[tangletools]

✅ Auto-approved drewstone PR — ed371372

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 · 2026-07-08T20:16:34Z}