- SessionManager owns all ClientContexts; callers must not store references
- IsAuthenticated(tenantUrl) returns false before auth, true after GetOrCreateContextAsync
- ClearSessionAsync disposes ClientContext and removes state (idempotent for unknown tenants)
- GetOrCreateContextAsync validates null/empty TenantUrl and ClientId (ArgumentException)
- MsalClientFactory.GetCacheHelper() added — exposes helper for PnP tokenCacheCallback wiring
- 8 unit tests pass, 1 interactive-login test skipped (integration-only)
- LoggingIntegrationTests: verifies Serilog writes rolling log file with correct content
- LogPanelSink structural smoke test: confirms type implements ILogEventSink
- App.xaml.cs: added comment for LogPanelSink DI registration deferred to plan 01-06
- Instance singleton test
- EN string lookup test
- FR culture fallback test
- Missing key returns bracketed key
- PropertyChanged fires with empty string on culture switch
- Same culture does not fire PropertyChanged