Update ROADMAP.md: Mark Issue #63 (z-order rendering) as complete

- Add z-order rendering to recent achievements
- Update alpha blocker count from 3 to 2
- Archive z-order test files
- Next priority: RenderTexture concept (#6) - last major alpha blocker

ROADMAP.md

@@ -3,7 +3,7 @@
 ## Project Status: Post-7DRL 2025 "Crypt of Sokoban"
 
 **Current State**: Successful 7DRL completion with Python/C++ game engine  
-**Latest Update**: Python Sequence Protocol complete! Issue #69 resolved (2025-07-05)  
+**Latest Update**: Z-order rendering complete! Issue #63 resolved (2025-07-05)  
 **Branch**: interpreter_mode (full sequence protocol for collections + default values)  
 **Open Issues**: ~46 remaining from original 64 (closed 16 + fixed 14 previously)
 
@@ -11,6 +11,14 @@
 
 ## Recent Achievements
 
+### 2025-07-05: Z-order Rendering Complete! 🎉
+**Issue #63 Resolved**: Consistent z-order rendering with performance optimization
+- Dirty flag pattern prevents unnecessary per-frame sorting
+- Lazy sorting for both Scene elements and Frame children
+- Frame children now respect z_index (fixed inconsistency)
+- Automatic dirty marking on z_index changes and collection modifications
+- Performance: O(1) check for static scenes vs O(n log n) every frame
+
 ### 2025-07-05: Python Sequence Protocol Complete! 🎉
 **Issue #69 Resolved**: Full sequence protocol implementation for collections
 - Complete __setitem__, __delitem__, __contains__ support
@@ -97,9 +105,9 @@ Created comprehensive test suite with 13 tests covering all Python-exposed metho
 
 ## 🚧 NEXT PRIORITY: Alpha Release Blockers
 
-### Remaining Alpha Blockers (3 issues):
+### Remaining Alpha Blockers (2 issues):
 1. ~~**#69** - Python Sequence Protocol for collections~~ - *Completed! (2025-07-05)*
-2. **#63** - Z-order rendering for UIDrawables - *Multiple Integrations*
+2. ~~**#63** - Z-order rendering for UIDrawables~~ - *Completed! (2025-07-05)*
 3. ~~**#59** - Animation system~~ - *Completed! (2025-07-05)*
 4. **#6** - RenderTexture concept - *Extensive Overhaul*
 5. ~~**#47** - New README.md for Alpha release~~ - *Completed*
@@ -122,11 +130,11 @@ Created comprehensive test suite with 13 tests covering all Python-exposed metho
 
 ---
 
-## 🎯 ALPHA 0.1 RELEASE BLOCKERS (3 Remaining)
+## 🎯 ALPHA 0.1 RELEASE BLOCKERS (2 Remaining)
 
 ### ⚠️ Must Complete Before Alpha Release
 - [x] **#69** - Collections use Python Sequence Protocol - *Completed! (2025-07-05)*
-- [ ] **#63** - Z-order rendering for UIDrawables - *Multiple Integrations*  
+- [x] **#63** - Z-order rendering for UIDrawables - *Completed! (2025-07-05)*  
 - [x] **#59** - Animation system for arbitrary UIDrawable fields - *Completed! (2025-07-05)*
 - [ ] **#6** - RenderTexture concept for all UIDrawables - *Extensive Overhaul*
 - [x] **#47** - New README.md for Alpha release - *Completed*
@@ -338,7 +346,7 @@ REMAINING IN PHASE 1:
 
 *Last Updated: 2025-07-05*  
 *Total Open Issues: 62* (from original 78)  
-*Alpha Blockers: 3* (was 7 - completed #69 Sequence Protocol, #59 Animation, #47 README, #3/#2 deprecated methods)  
+*Alpha Blockers: 2* (was 7 - completed #69 Sequence Protocol, #59 Animation, #63 Z-order, #47 README, #3/#2 deprecated methods)  
 *Current Work: Python Sequence Protocol complete! Full collection behavior with slicing, operators, and type safety*  
-*Next Session: Z-order rendering (#63) or RenderTexture concept (#6)*
+*Next Session: RenderTexture concept (#6) - Last major alpha blocker!*