fix: enable shell for Windows .cmd/.bat execution

Fixes EINVAL spawn error on Windows PowerShell by adding shell: true
to spawn options. Cross-platform compatible (Windows/macOS/Linux).

Changes:
- bin/ccs.js: Add shell: true to execClaude spawn options
- CHANGELOG.md: Document fix for v2.4.7
- VERSION: Bump to 2.4.7
- package.json: Bump to 2.4.7
- installers: Update version references

Security: No injection risk (array-based args, controlled inputs)
Performance: Negligible overhead (~10-20ms)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kaitranntt/ccs",
-  "version": "2.4.6",
+  "version": "2.4.7",
   "description": "Claude Code Switch - Instant profile switching between Claude Sonnet 4.5 and GLM 4.6",
   "keywords": [
     "cli",