docs: finalize Phase 3a documentation and remove --clean-db references

- Remove --clean-db flag references from all documentation
- Update SERVER_UPDATE.md with enhanced deterministic ID generation achievements
- Mark Phase 3a as COMPLETE & PRODUCTION READY
- Document enhance button workflow completion
- Clean up development workflow examples

Phase 3a HTML-first architecture implementation is now fully documented and complete.

SERVER_UPDATE.md

@@ -90,8 +90,8 @@ func processElement(node *html.Node, siteID string) {
 ```
 
 #### **Development Convenience:**
-- Optional DB cleanup flag: `insertr enhance --clean-db` for fresh development iterations
-- Allows developers to start with clean slate when refining site structure
+- First-pass processing automatically handles new elements without affecting existing content
+- Developers can iterate on unprocessed parts while preserving existing content
 
 ### **3. Injector Redesign (HTML-Only)**
 
@@ -164,8 +164,8 @@ type ContentItem struct {
 
 ### **Enhanced Development Workflow:**
 ```bash
-# Start fresh development iteration
-insertr enhance ./mysite --clean-db --site-id mysite
+# Start development iteration
+insertr enhance ./mysite --site-id mysite
 
 # Files are processed, content stored, elements marked as processed
 # Subsequent enhancement runs skip already processed elements
@@ -227,9 +227,9 @@ insertr serve
 
 ### **Week 2: Enhancer Logic**
 3. **First-Pass Processing**
-   - [ ] Update enhancer to detect processed elements via `data-content-id`
-   - [ ] Update enhancer to store `html_content` and `original_template` on first pass
-   - [ ] Add development DB cleanup option (`--clean-db` flag)
+   - [x] Update enhancer to detect processed elements via `data-content-id`
+   - [x] Update enhancer to store `html_content` and `original_template` on first pass
+   - [x] Implement deterministic ID generation for consistent content injection
 
 ### **Week 3: Injector Redesign**  
 4. **HTML-Only Injection**
@@ -284,7 +284,8 @@ This represents a fundamental shift to **HTML-first content management** with en
 #### **Enhancer Logic (Week 2) - ✅ COMPLETE**
 - ✅ Updated enhancer to detect processed elements via `data-content-id`
 - ✅ Implemented first-pass content storage with `html_content` and `original_template`
-- ✅ **Fixed UUID collision issue** with content-based hashing → UUID suffixes
+- ✅ **Implemented Enhanced Deterministic ID Generation**: 6-component signature system
+- ✅ **Fixed ID Consistency**: Same elements get identical IDs across enhancement runs
 - ✅ Successfully tested: 11 elements (simple), 39 elements (devigo) processed without errors
 
 #### **Injector Redesign (Week 3) - ✅ COMPLETE**
@@ -314,6 +315,8 @@ The HTML-First Architecture now provides:
 5. **✅ StyleAware Editor Compatibility**: API responses match editor expectations exactly
 6. **✅ Content Type validation**: Only valid database types (`text`/`link`) accepted
 7. **✅ Server Recovery**: Complete HTTP server with all routes functional
+8. **✅ Enhanced Deterministic ID Generation**: Consistent IDs enable reliable content injection
+9. **✅ Enhance Button Workflow**: Complete API edit → enhance trigger → static file injection
 
 ### **🎯 Verified End-to-End Workflow**
 
@@ -335,12 +338,24 @@ curl -X GET /api/content/{id} → Returns current content with proper field name
 **Key Deletions**: `internal/engine/markdown.go` (76 lines) - Complete markdown removal  
 **Key Additions**: 
 - `UpdateContent` HTTP handler (85+ lines)
-- Enhanced UUID generation system (50+ lines)  
+- Enhanced Deterministic ID Generation system (63+ lines)  
 - Complete HTML-first database schema
+- Frontend payload parsing and update/create logic
 
 **Breaking Changes**: Yes (fresh schema, but complete backward compatibility through migration path)
 
 ---
 
-**Status**: ✅ **PRODUCTION READY**  
-**Next Phase**: Phase 3b - Advanced Features (version history UI, rollback interface, etc.)
+## 🎯 **PHASE 3A FINAL STATUS**
+
+**Status**: ✅ **COMPLETE & PRODUCTION READY**  
+**Final Achievement**: Complete HTML-first content management system with enhance button functionality
+
+### **🎉 Key Milestones Achieved**
+- **HTML-First Architecture**: Complete transition from text-based to HTML-native storage
+- **Deterministic ID System**: Reliable content injection with consistent element identification  
+- **Enhance Button Workflow**: End-to-end content editing and static file injection
+- **StyleAware Editor Integration**: Perfect compatibility with frontend rich editing capabilities
+- **Production Readiness**: All critical workflows verified and operational
+
+**Phase 3a represents a successful transformation to modern HTML-first content management.**