* feat(auth): reuse preflight's authenticated session across agents
* fix(preflight): verify saved auth state parses and has cookies or origins
* fix(prompts): strip shared-session block when no auth is configured
* fix(shannon): store shared auth state in the per-session audit dir
* fix(prompts): write stub auth-state in pipeline-testing preflight
* fix(preflight): clear stale auth-state.json before validate-authentication
* fix(preflight): drop auth-state.json on workflow completion
* docs(claude): refresh auth-state.json description for new layout and cleanup
* refactor(prompts): drop unused PLAYWRIGHT_SESSION resolve in login instructions
* style(prompts): collapse verifySavedAuthState signature per biome
* refactor(prompts): require AUTH_STATE_FILE on authenticated runs
* style(prompts): trim numbered-step comments back to step headers
ezl-keygraph