docs(15): create consolidation data model phase plans

Two plans for Phase 15: models + consolidator service (wave 1), unit tests + build verification (wave 2).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -60,7 +60,10 @@
   2. A `PermissionConsolidator` service accepts a flat list of permission rows and returns a consolidated list where duplicate user+level rows are merged
   3. Consolidation logic has unit test coverage — a known 10-row input with 3 duplicate pairs produces the expected 7-row output
   4. Existing HTML export services compile and produce identical output when consolidation is not applied (opt-in, defaults off)
-**Plans**: TBD
+**Plans:** 2 plans
+Plans:
+- [ ] 15-01-PLAN.md — Models (LocationInfo, ConsolidatedPermissionEntry) + PermissionConsolidator service
+- [ ] 15-02-PLAN.md — Unit tests (10 test cases) + full solution build verification
 
 ### Phase 16: Report Consolidation Toggle
 **Goal**: Users can choose to merge duplicate permission entries per export through a toggle in the export settings dialog
@@ -114,7 +117,7 @@
 | 1-5 | v1.0 | 36/36 | Shipped | 2026-04-07 |
 | 6-9 | v1.1 | 25/25 | Shipped | 2026-04-08 |
 | 10-14 | v2.2 | 14/14 | Shipped | 2026-04-09 |
-| 15. Consolidation Data Model | v2.3 | 0/? | Not started | — |
+| 15. Consolidation Data Model | v2.3 | 0/2 | Planning | — |
 | 16. Report Consolidation Toggle | v2.3 | 0/? | Not started | — |
 | 17. Group Expansion in HTML Reports | v2.3 | 0/? | Not started | — |
 | 18. Auto-Take Ownership | v2.3 | 0/? | Not started | — |