Add optional Claude Code installation with Z.AI API support

Features:
- New install-claude-code.sh script for automated Claude Code installation
- Z.AI API integration (GLM models: glm-4.5-air, glm-4.7)
- Automated and manual installation modes
- Supercharge.sh now offers to install Claude Code if not present
- Updated README with comprehensive Claude Code installation guide

Z.AI Models:
- glm-4.5-air: Fast, efficient model (Haiku class)
- glm-4.7: Powerful model (Sonnet/Opus class)

Documentation: https://docs.z.ai/devpack/tool/claude

README.md

@@ -77,6 +77,62 @@ cd SuperCharged-Claude-Code-Upgrade
 ./supercharge.sh --dev-mode
 ```
 
+## Claude Code Installation (Optional)
+
+If you don't have Claude Code installed yet, the supercharge script will offer to install it for you with **Z.AI API support**.
+
+### What is Z.AI API?
+
+Z.AI provides GLM (General Language Model) models that can be used with Claude Code:
+
+- **glm-4.5-air** - Fast, efficient model (Haiku class)
+- **glm-4.7** - Powerful model (Sonnet/Opus class)
+
+### Automated Installation
+
+```bash
+# Install Claude Code with Z.AI API
+./install-claude-code.sh --auto
+
+# You'll be prompted for your Z.AI API key
+# Get your API key from: https://docs.z.ai/devpack/tool/claude
+```
+
+### Manual Installation
+
+```bash
+# 1. Install Claude Code via npm
+npm install -g @anthropic-ai/claude-code
+
+# 2. Configure Z.AI API
+# Create or edit ~/.claude/settings.json:
+{
+  "env": {
+    "ANTHROPIC_API_KEY": "your-zai-api-key-here",
+    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "glm-4.5-air",
+    "ANTHROPIC_DEFAULT_SONNET_MODEL": "glm-4.7",
+    "ANTHROPIC_DEFAULT_OPUS_MODEL": "glm-4.7"
+  }
+}
+
+# 3. Start Claude Code
+claude
+
+# 4. Check model status
+/status
+```
+
+### Show Manual Instructions Only
+
+```bash
+./install-claude-code.sh --manual
+```
+
+### Documentation
+
+- **Z.AI Official Docs**: https://docs.z.ai/devpack/tool/claude
+- **Claude Code Docs**: https://docs.anthropic.com/en/docs/claude-code/overview
+
 ## What Gets Installed
 
 ### Directory Structure