docs(10-03): complete branding-data-foundation plan 03

- 10-03-SUMMARY.md: DI registration for Phase 10 services
- STATE.md: advanced position, added decision, updated session
- ROADMAP.md: phase 10 marked complete (3/3 plans)

.planning/phases/10-branding-data-foundation/10-03-SUMMARY.md

@@ -0,0 +1,114 @@
+---
+phase: 10-branding-data-foundation
+plan: "03"
+subsystem: infra
+tags: [di, dependency-injection, ioc-container, branding, graph-directory, wpf]
+
+# Dependency graph
+requires:
+  - phase: 10-branding-data-foundation-01
+    provides: "BrandingRepository, IBrandingService/BrandingService"
+  - phase: 10-branding-data-foundation-02
+    provides: "IGraphUserDirectoryService/GraphUserDirectoryService"
+
+provides:
+  - "BrandingRepository registered as Singleton in DI (branding.json path)"
+  - "IBrandingService/BrandingService registered as Singleton in DI"
+  - "IGraphUserDirectoryService/GraphUserDirectoryService registered as Transient in DI"
+  - "Phase 10 services fully wired — resolvable at runtime"
+
+affects:
+  - phase-11-report-branding
+  - phase-13-user-directory-viewmodel
+  - phase-14-user-directory-ui
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - "Phase 10 DI block placed after SettingsRepository, before MsalClientFactory — grouped with other repository/infrastructure singletons"
+    - "BrandingRepository: Singleton lifetime matching ProfileRepository/SettingsRepository (single file, shared SemaphoreSlim)"
+    - "IBrandingService: Singleton lifetime — stateless after construction, depends on singleton BrandingRepository"
+    - "IGraphUserDirectoryService: Transient lifetime — stateless, per-call, designed for multiple-tenant scenarios"
+
+key-files:
+  created: []
+  modified:
+    - SharepointToolbox/App.xaml.cs
+
+key-decisions:
+  - "No new using statements required — SharepointToolbox.Infrastructure.Persistence and SharepointToolbox.Services were already imported from prior phases"
+
+patterns-established:
+  - "Phase section comment pattern: each new phase block labeled with '// Phase N: Name' comment for orientation in RegisterServices"
+
+requirements-completed:
+  - BRAND-01
+  - BRAND-03
+  - BRAND-06
+
+# Metrics
+duration: 5min
+completed: 2026-04-08
+---
+
+# Phase 10 Plan 03: DI Registration Summary
+
+**BrandingRepository (Singleton), IBrandingService (Singleton), and IGraphUserDirectoryService (Transient) wired into App.xaml.cs — 224 tests pass, zero regressions**
+
+## Performance
+
+- **Duration:** ~5 min
+- **Started:** 2026-04-08T10:34:43Z
+- **Completed:** 2026-04-08T10:39:00Z
+- **Tasks:** 1
+- **Files modified:** 1
+
+## Accomplishments
+
+- All three Phase 10 services registered in the application's DI container with correct lifetimes
+- Main project builds with zero warnings under `-warnaserror`
+- Full test suite: 224 passed, 26 skipped (integration tests requiring live Graph), 0 failed
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Register Phase 10 services in DI and run full test suite** - `7e8e228` (feat)
+
+## Files Created/Modified
+
+- `SharepointToolbox/App.xaml.cs` - Added Phase 10 DI block: BrandingRepository (Singleton, branding.json), IBrandingService/BrandingService (Singleton), IGraphUserDirectoryService/GraphUserDirectoryService (Transient)
+
+## Decisions Made
+
+None - followed plan as specified. The `using` directives for `SharepointToolbox.Infrastructure.Persistence` and `SharepointToolbox.Services` were already present, so no additional imports were needed.
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+
+One flaky test failure (`CanExport_true_when_has_results`) occurred during the first full suite run. This test uses `WeakReferenceMessenger` with async ViewModel operations and is timing-sensitive. Re-running the specific test and then the full suite both passed. The failure was not caused by my DI changes (the test uses direct constructor injection with mocks — no DI container involved). The test passed on all subsequent runs.
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- All Phase 10 services resolve at runtime without errors
+- Phase 11 (report branding) can inject `IBrandingService` into export services and ViewModels
+- Phase 13 (user directory ViewModel) can inject `IGraphUserDirectoryService`
+- BrandingRepository will create `branding.json` on first write, in the existing AppData directory — no manual setup needed
+
+---
+*Phase: 10-branding-data-foundation*
+*Completed: 2026-04-08*
+
+## Self-Check: PASSED
+
+- FOUND: SharepointToolbox/App.xaml.cs (with Phase 10 registrations)
+- FOUND: .planning/phases/10-branding-data-foundation/10-03-SUMMARY.md
+- FOUND commit: 7e8e228 (feat(10-03): register Phase 10 services in DI container)