docs: add v02.00.00 roadmap — migration script removal

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

docs/ROADMAP.md

@@ -144,6 +144,25 @@ This document provides a comprehensive, version-specific roadmap for the MokoOny
 
 The following versions represent our planned annual major releases, each building upon the previous version's foundation.
 
+#### v02.00.00 (Q3 2026) - Clean Slate
+**Status**: Planned
+**Target Release**: Q3 2026
+
+**Breaking Changes**:
+- **Remove MokoCassiopeia migration script** — the `helper/migrate.php` bootstrap in `index.php` and the `.migrated` marker file will be removed. All MokoCassiopeia users must migrate before upgrading to v02.
+- **Remove MokoCassiopeia references** — all `str_replace(mokocassiopeia, mokoonyx)` logic, old name constants, and legacy compatibility code will be cleaned out.
+- **Remove `script.php` bridge logic** — the `postflight()` migration code for MokoCassiopeia will be removed.
+
+**New Features**:
+- Clean codebase with no migration overhead
+- Performance improvements from removing first-load migration check
+- Fresh start for MokoOnyx-native development
+
+**Migration Notice**:
+Users still running MokoCassiopeia must install MokoOnyx v01.x first to migrate their settings before upgrading to v02. The v01.x line will remain available for download.
+
+---
+
 #### v04.00.00 (Q4 2027) - Enhanced Accessibility & Performance
 **Status**: Planned  
 **Target Release**: December 2027