- 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)
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