v0.3.1 - badge immediacy + test harness

Focus: community merges + proof-of-work (two contributors in 24 h ??)

• Faster model-switch badges (PR #13, thanks @Golden007-prog) - a running session's badge now follows session.model* events immediately, no paginated session-list, no 8-second lag; incomplete payloads keep the short refresh, and an in-flight stale list can no longer restore an old mapping. Closes #11.
• Test harness on main (idea from PR #5, thanks @xmejl) - dependency-free npm test (node:test): 20 tests across badge strip/pick/count + real-plugin model-switch regressions. The suffix-regex and dedup findings are credited in lib.ts, the test header and CONTRIBUTING.md.
• CI gate - .github/workflows/test.yml runs the suite on every push/PR (Node 22 + 24). Green badge on the README.
• Quality-of-readme - badges row (license/version/tests/node), updated install copy includes lib.ts.

Credits

Contributor	What
@xmejl	double-count reproduction + suffix regex bug (PR #5, absorbed with credit)
@Golden007-prog	immediate model-switch badge updates + revision guard (PR #13)

Full changelog: v0.3.0...v0.3.1