docs(17-02): complete group expansion HTML reports plan

- 17-02-SUMMARY.md created
- STATE.md updated: session, decisions, progress
- ROADMAP.md: phase 17 marked complete (2/2 plans)
- REQUIREMENTS.md: RPT-01 marked complete

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v2.3
 milestone_name: Tenant Management & Report Enhancements
 status: planning
-stopped_at: Completed 17-01-PLAN.md
-last_updated: "2026-04-09T11:06:09.877Z"
+stopped_at: Completed 17-02-PLAN.md
+last_updated: "2026-04-09T11:11:11.458Z"
 last_activity: 2026-04-09 — Roadmap created for v2.3 (phases 15-19)
 progress:
   total_phases: 5
-  completed_phases: 2
+  completed_phases: 3
   total_plans: 6
-  completed_plans: 5
+  completed_plans: 6
 ---
 
 # Project State
@@ -70,6 +70,7 @@ Decisions are logged in PROJECT.md Key Decisions table.
 - [Phase 16-report-consolidation-toggle]: Separate locIdx counter for location groups (loc0, loc1...) distinct from grpIdx for user groups (ugrp0...) prevents ID collision
 - [Phase 17]: Static helpers IsAadGroup/ExtractAadGroupId/StripClaims declared internal to enable unit testing via InternalsVisibleTo without polluting public API
 - [Phase 17]: Graph client created lazily on first AAD group encountered to avoid unnecessary auth overhead for groups with no nested AAD members
+- [Phase 17]: groupMembers optional param in HtmlExportService — null produces identical pre-Phase-17 output; ISharePointGroupResolver injected as optional last param in PermissionsViewModel; resolution failure degrades gracefully with LogWarning
 
 ### Pending Todos
 
@@ -81,7 +82,7 @@ None.
 
 ## Session Continuity
 
-Last session: 2026-04-09T11:06:05.361Z
-Stopped at: Completed 17-01-PLAN.md
+Last session: 2026-04-09T11:11:03.823Z
+Stopped at: Completed 17-02-PLAN.md
 Resume file: None
 Next step: `/gsd:plan-phase 15`