chore: clean up TODO.md by removing completed theme system refactor tasks

Remove outdated theme system refactor content from TODO.md since the layered
theme architecture work was already completed and released in v0.6.0. The
todofile is now clean and ready for new active development tasks.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

TODO.md

@@ -13,30 +13,7 @@ The structure organizes **future tasks** by their impact, just as a changelog or
 This section is for tasks currently being discussed with or worked on by the coding assistant. These are the ephemeral, flow-of-thought tasks.
 
 * **To Add:**
-    * **Complete Theme System Refactor - Layered Theme Architecture**: Major refactor to replace simple template selection with sophisticated layered theme system (currently stashed)
-        * **Phase 1 - Restore and Assess**:
-            * Restore stashed changes with `git stash pop`
-            * Run tests to identify current failures and validation issues
-            * Assess remaining work by checking all files that still use `--template`
-        * **Phase 2 - Complete CLI Parameter Migration**:
-            * Update remaining CLI commands in asset_commands.py, cli.py, and other files
-            * Fix parameter validation - add proper theme validation for the new string-based parameter
-            * Update help text and documentation to reflect new layered theme capabilities
-        * **Phase 3 - Fix Integration Issues**:
-            * Fix function signature mismatches where functions expect `template` but receive `theme`
-            * Add proper error handling for invalid themes (replace print statements with logging)
-            * Test layered theme functionality - ensure `dark,academic` type combinations work
-            * Verify legacy theme mapping works correctly
-        * **Phase 4 - Quality Assurance**:
-            * Run full test suite to ensure no regressions
-            * Test all CLI commands with new theme parameter
-            * Verify backward compatibility with existing templates
-            * Update any remaining documentation
-        * **Phase 5 - Clean Up and Commit**:
-            * Remove dead code and legacy functions if no longer needed
-            * Ensure consistent terminology throughout codebase
-            * Write comprehensive commit message documenting the major theme system improvement
-            * Update CHANGELOG.md with new theme layering capabilities
+    * None currently identified
 
 * **To Fix:**
     * None currently identified
@@ -47,30 +24,6 @@ This section is for tasks currently being discussed with or worked on by the cod
 * **To Remove:**
     * None currently identified
 
-***
-
-## Theme System Refactor Context
-
-**Current State**: Work-in-progress theme system refactor is stashed and partially complete.
-
-**Completed Parts ✅**:
-- New Layered Theme Architecture: Complete LAYERED_THEMES system with UI, document, and branding scopes
-- Theme Parsing Functions: `parse_theme_string()` and `combine_theme_properties()`
-- CSS Generation Refactor: New `_get_template_css()` and `_generate_layered_css()` methods
-- CLI Parameter Change: Changed from `--template` to `--theme` throughout test files
-- Legacy Compatibility: LEGACY_THEME_MAPPING for backward compatibility
-
-**Missing/Incomplete Parts ❌**:
-- CLI Parameter Validation: The new `--theme` parameter needs validation for invalid themes
-- Function Signature Inconsistencies: Some functions still accept `template` parameter but call it with `theme`
-- Additional Files: Other files in the codebase still use old `template` parameter
-- Error Handling: The warning system for unknown themes needs proper logging
-
-**New Capabilities When Complete**:
-- Single themes: `basic`, `github`, `dark`, `academic`, `light`, `corporate`, `startup`
-- Layered themes: `dark,academic` combines dark UI with academic typography
-- Complex combinations: `light,github,corporate` for branded GitHub-style documents
-- Legacy compatibility: Existing `--template` usage continues to work
 
 ***