fix: remove Node.js DEP0190 deprecation warning

Use platform-specific shell option (Windows only) instead of shell: true
to avoid deprecation warning in Node.js v22.9.0+.

Changes:
- bin/ccs.js: Change shell: true to shell: process.platform === 'win32'
- CHANGELOG.md: Document fix for v2.4.8
- VERSION: Bump to 2.4.8
- package.json: Bump to 2.4.8

Benefits:
- No deprecation warning on Windows
- Better performance on Unix (no shell overhead)
- Maintains Windows .cmd/.bat compatibility

lib/ccs

@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # Version (updated by scripts/bump-version.sh)
-CCS_VERSION="2.4.7"
+CCS_VERSION="2.4.8"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly CONFIG_FILE="${CCS_CONFIG:-$HOME/.ccs/config.json}"
 

lib/ccs.ps1

@@ -134,7 +134,7 @@ function Show-Help {
 }
 
 # Version (updated by scripts/bump-version.sh)
-$CcsVersion = "2.4.7"
+$CcsVersion = "2.4.8"
 $ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 $ConfigFile = if ($env:CCS_CONFIG) { $env:CCS_CONFIG } else { "$env:USERPROFILE\.ccs\config.json" }