security: Remove sensitive credentials and add .env.example

- Remove .env file with real API keys and bot token
- Add .env.example with placeholder values
- Verify .env is in .gitignore
- Repository is now safe to share with others

Environment variables:
- ZAI_API_KEY: Z.AI API key
- TELEGRAM_BOT_TOKEN: Telegram bot token
- TELEGRAM_ALLOWED_USERS: Allowed Telegram user IDs
- ZCODE_WEBHOOK_URL: Optional webhook URL
- ZCODE_PORT: Bot port (default: 3001)

Users must create their own .env file from .env.example

.env.example

@@ -0,0 +1,26 @@
+# Z.AI Configuration (Coding Plan)
+# Get your API key from https://z.ai/
+GLM_BASE_URL=https://api.z.ai/api/coding/paas/v4
+ZAI_API_KEY=your_zai_api_key_here
+
+# Telegram Bot Configuration
+# Get your bot token from @BotFather
+TELEGRAM_BOT_TOKEN=your_telegram_bot_token_here
+TELEGRAM_ALLOWED_USERS=your_telegram_user_id_here
+
+# zCode CLI X Configuration
+ZCODE_ENABLE_BASH=true
+ZCODE_ENABLE_FILE_EDIT=true
+ZCODE_ENABLE_WEB_SEARCH=true
+ZCODE_ENABLE_GIT=true
+
+# Optional: Webhook Configuration
+# ZCODE_WEBHOOK_URL=https://your-domain.com/telegram/webhook
+ZCODE_PORT=3001
+
+# Logging
+LOG_LEVEL=info
+LOG_FILE=logs/zcode.log
+
+# Agent Configuration
+ZCODE_MAX_CONCURRENT_AGENTS=3