feat: add npm postinstall config creation and restructure test suite

Configuration Management:
- Add npm postinstall script to auto-create ~/.ccs/ directory and config files
- Create config.json with default profile mappings (glm, default)
- Create glm.settings.json template with GLM API configuration
- Ensure idempotent postinstall behavior (safe to run multiple times)
- Fix config-manager.js to handle missing config.json gracefully

Test Suite Restructure:
- Reorganize tests by installation method (native vs npm)
- Move 37 native Unix tests to tests/native/unix/
- Move Windows tests to tests/native/windows/
- Move 39 npm package tests to tests/npm/
- Move shared utilities to tests/shared/
- Add comprehensive test documentation and README
- Implement master orchestrators for backward compatibility
- Increase test coverage from 41 to 83+ tests (100% increase)
- Add mocha framework for npm tests with better assertions

New Test Commands:
- npm run test:npm (npm package tests only)
- npm run test:native (native tests only)
- npm run test:unit (unit tests only)
- npm run test:all (all tests)

Backward Compatibility:
- npm test (runs all tests)
- bash tests/edge-cases.sh (master orchestrator)
- All existing workflows unchanged

Version: 2.4.4

lib/ccs

@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # Version (updated by scripts/bump-version.sh)
-CCS_VERSION="2.4.3"
+CCS_VERSION="2.4.4"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 # --- Color/Format Functions ---

lib/ccs.ps1

@@ -72,7 +72,7 @@ Restart your terminal after installation.
 }
 
 # Version (updated by scripts/bump-version.sh)
-$CcsVersion = "2.4.3"
+$CcsVersion = "2.4.4"
 $ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 
 # Installation function for commands and skills