feat: add API keys management and config CRUD operations

- Add api_keys and feishu_apps to config.json
- Add env export/init commands for shell integration
- Add config CRUD: list, set, delete, init
- Add config.json.example template
- Add config.json to .gitignore for security
- Update README with new commands

Usage:
  mycli env export              # Export all env vars
  mycli config set key value    # Set config value
  mycli config delete key       # Delete config key

README.md

@@ -64,13 +64,31 @@ mycli self update           # Update mycli
 mycli self uninstall        # Uninstall mycli
 mycli self info             # Show installation info
 
-# Configuration (config.json)
-mycli config show           # Show full config
-mycli config get paths      # Get paths section
-mycli config get paths.apaam # Get specific path
-mycli config paths          # List all paths with existence check
-mycli config where          # Show config file location
-mycli config edit           # Edit config in $EDITOR
+# Configuration (config.json) - 增删改查
+mycli config show                   # Show full config
+mycli config list                   # List top-level sections
+mycli config get paths              # Get paths section
+mycli config get paths.apaam        # Get specific path
+mycli config get api_keys.deepseek  # Get API key
+mycli config set paths.new ~/Documents/new      # Set simple value
+mycli config set api_keys.newkey abc123         # Set new API key
+mycli config set --json ssh_hosts.new '{"host":"user@host","port":22}'
+mycli config delete paths.old                   # Delete a key
+mycli config delete api_keys.old -y             # Delete without confirmation
+mycli config paths                  # List all paths with existence check
+mycli config where                  # Show config file location
+mycli config edit                   # Edit config in $EDITOR
+mycli config init                   # Create config from template
+
+# Environment Variables (API Keys)
+mycli env status                    # Show paths, API keys, Feishu status
+mycli env export                    # Print all export statements
+mycli env export deepseek           # Export specific API key
+mycli env export qwen
+mycli env export feishu             # Export all Feishu apps
+mycli env export claude             # Export specific Feishu app
+eval "$(mycli env export)"          # Load all in current shell
+mycli env init                      # Print shell init snippet
 ```
 
 ## Configuration
@@ -80,6 +98,30 @@ All settings are stored in `mycli/config.json`:
 - `ssh_hosts`: SSH connection settings
 - `git_proxies`: Git proxy URLs
 - `openfoam`: OpenFOAM mount settings
+- `api_keys`: API keys (deepseek, qwen)
+- `feishu_apps`: Feishu app credentials
+
+### Security Note
+
+`config.json` contains sensitive information (API keys) and is **gitignored**. 
+The repository includes `config.json.example` as a template.
+
+### Setup
+
+1. Copy the example config:
+   ```bash
+   cp mycli/config.json.example mycli/config.json
+   ```
+
+2. Edit with your actual API keys:
+   ```bash
+   mycli config edit
+   ```
+
+3. Add to your `~/.zshrc` to auto-load:
+   ```bash
+   eval "$(mycli env export 2>/dev/null)"
+   ```
 
 ## Uninstall