chore: merge main into hunleyd/fix/caveman-compress-concurrent-write-lock

* origin/main: (68 commits)
  Cleanup
  fix(proxy): scope repo intelligence to project source and require direct evidence (#901)
  chore(release): cut @caveman-ai/cli 1.2.5
  fix(cli): revive a dead local proxy mid-session, not just at SessionStart
  fix(install): pin the shims at v2.3.1 and guard against pin drift
  chore: sync SKILL.md copies [skip ci]
  chore(release): cut v2.3.0 on the bin-v1.1.3 runtime
  skill + docs update
  chore(docs): remove the GitHub Pages landing page
  docs: add the Cursor Tier 1 support plan
  docs: mark learn v3 as shipped
  chore(cli): regenerate the bundled agent skill registry
  refactor(skills): rewrite the caveman ruleset's framing clauses
  feat(skills): teach caveman-learn to report spend and attributed savings
  feat(cli): surface learn spend, the savings ledger, and holdout reports
  docs(proxy): record the spend-vs-savings rule for local learn
  feat(proxy): log serve-mode warnings to ~/.caveman/proxy.log
  fix(proxy/gateway): buffer non-streaming upstream bodies before replying
  feat(proxy/store): show spend and attribution in the learn report
  feat(proxy/store): add a privacy-safe export digest
  ...