docs(readme): add CI, release, and license badges

[imlach]

CI / release / license badges for the public README. Also the first dogfood review in the public repo — labeled review-deep to exercise the full loop on the public infrastructure wiring.

[github-actions]

cora review

🟢 looks good

The three badges (CI, release, license) all reference valid paths: .github/workflows/ci.yml exists, the LICENSE file is present, and the Shields.io release badge uses the correct repo owner/repo. No code or config changes — just a README addition.

Findings:

• ℹ️ Note: The CI badge URL uses the imlach/cora owner — once merged to main and the repo is public, this will resolve correctly. If this PR is being reviewed on a fork before merge, the badge will show "unknown" until the merge lands.

mode: deep · endpoint: review (review-elastic-3090) · 5 calls across 1 tool (9/10 unused) · ~24093 in / ~945 out tokens · 16.0s wall
started 2026-07-03 11:44:49 UTC · context: retrieval (empty) · logs

used: grep_repo×5
unused: git_log, git_show, list_decisions, list_notes, read_agents_section, read_decision, read_note, search_cluster_docs, search_knowledge