chore: complete v1.0 milestone

Archive 5 phases (36 plans) to milestones/v1.0-phases/.
Archive roadmap, requirements, and audit to milestones/.
Evolve PROJECT.md with shipped state and validated requirements.
Collapse ROADMAP.md to one-line milestone summary.

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

.planning/MILESTONES.md

@@ -0,0 +1,23 @@
+# Milestones
+
+## v1.0 MVP (Shipped: 2026-04-07)
+
+**Phases completed:** 5 phases, 36 plans | 164 commits | 10,071 LOC (C# + XAML)
+**Timeline:** 28 days (2026-03-10 → 2026-04-07)
+**Tests:** 134 pass, 22 skip (live CSOM), 0 fail
+
+**Key accomplishments:**
+- Full C#/WPF rewrite of 6,400-line PowerShell tool into 10,071-line MVVM application
+- Multi-tenant MSAL authentication with per-tenant token caching and instant switching
+- SharePoint permissions scanner with multi-site support, CSV/HTML export, 5,000-item pagination
+- Storage metrics, file search, and duplicate detection with configurable depth and exports
+- Bulk operations (members, sites, file transfer) with per-item error reporting, retry, and cancellation
+- Self-contained 200 MB EXE with full EN/FR localization (199 keys each)
+
+**Archives:**
+- [v1.0-ROADMAP.md](milestones/v1.0-ROADMAP.md)
+- [v1.0-REQUIREMENTS.md](milestones/v1.0-REQUIREMENTS.md)
+- [v1.0-MILESTONE-AUDIT.md](milestones/v1.0-MILESTONE-AUDIT.md)
+
+---
+