chore: release v2.4.6 with improved npm compatibility and fixes

- fix color detection for cross-platform TTY compatibility
- enhance help command with npm-specific content and npx examples
- remove --install/--uninstall flags pending .claude/ integration testing
- update version across all files and documentation
- preserve implementation code for future release readiness

docs/project-overview-pdr.md

@@ -61,8 +61,8 @@ Provide developers with instant, zero-downtime switching between AI models, opti
 - **Acceptance Criteria**:
   - `ccs --version` displays version and installation location
   - `ccs --help` shows usage information
-  - `ccs --install` integrates with Claude Code commands
-  - `ccs --uninstall` removes Claude Code integration
+  - **WIP**: `ccs --install` integrates with Claude Code commands (testing incomplete)
+  - **WIP**: `ccs --uninstall` removes Claude Code integration (testing incomplete)
 
 #### FR-006: Error Handling
 **Requirement**: System shall provide clear, actionable error messages