docs(19-01): complete AppRegistrationService plan execution

- 19-01-SUMMARY.md: service layer implementation with rollback pattern
- STATE.md: progress 98%, decisions added, session updated
- ROADMAP.md: phase 19 in-progress (1/2 plans)
- REQUIREMENTS.md: APPREG-02, APPREG-03, APPREG-06 marked complete

.planning/ROADMAP.md

@@ -117,7 +117,7 @@ Plans:
   3. Registration creates the Azure AD application, service principal, and grants all required API permissions in a single atomic operation — if any step fails, all partial changes are rolled back and the user sees a specific error explaining what failed and why
   4. A "Remove App" action in the profile dialog removes the Azure AD application registration from the target tenant
   5. After removal, all cached MSAL tokens and session state for that tenant are cleared, and subsequent operations require re-authentication
-**Plans:** 2 plans
+**Plans:** 1/2 plans executed
 Plans:
 - [ ] 19-01-PLAN.md — IAppRegistrationService + AppRegistrationResult model + TenantProfile.AppId + service implementation + unit tests
 - [ ] 19-02-PLAN.md — ViewModel RegisterApp/RemoveApp commands + XAML dialog UI + fallback panel + localization + VM tests
@@ -133,4 +133,4 @@ Plans:
 | 16. Report Consolidation Toggle | v2.3 | 2/2 | Complete | 2026-04-09 |
 | 17. Group Expansion in HTML Reports | 2/2 | Complete    | 2026-04-09 | — |
 | 18. Auto-Take Ownership | 2/2 | Complete    | 2026-04-09 | — |
-| 19. App Registration & Removal | v2.3 | 0/2 | Planned | — |
+| 19. App Registration & Removal | 1/2 | In Progress|  | — |