🧪 test: add JWT secret rotation BDD scenarios and step implementations (#12)

✨ merge: implement JWT secret rotation with BDD scenario isolation

- Implement JWT secret rotation mechanism (closes #8)
- Add per-scenario state isolation for BDD tests (closes #14)
- Validate password reset workflow via BDD tests (closes #7)
- Fix port conflicts in test validation
- Add state tracer for debugging test execution
- Document BDD isolation strategies in ADR 0025
- Fix PostgreSQL configuration environment variables

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>
Co-authored-by: Gabriel Radureau <arcodange@gmail.com>
Co-committed-by: Gabriel Radureau <arcodange@gmail.com>

.gitignore

@@ -23,6 +23,11 @@ server.pid
 *.log
 pkg/server/docs/
 
+# BDD test files
+features/**/*-config.yaml
+test-config.yaml
+test-v2-config.yaml
+
 # CI/CD runner configuration
 config/runner
 .runner