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

mycli/commands/config_cmd.py

@@ -2,10 +2,12 @@
 
 import json
 import os
+from pathlib import Path
 
 import click
 
 from mycli.config import config
+from mycli.utils import handle_errors
 
 
 @click.group(name="config")
@@ -23,7 +25,13 @@ def show():
 @config_cmd.command("get")
 @click.argument("key")
 def get_value(key):
-    """Get a configuration value by key (dot notation)."""
+    """Get a configuration value by key (dot notation).
+
+    Examples:
+        mycli config get paths.research
+        mycli config get ssh_hosts.tianhe.port
+        mycli config get api_keys.deepseek
+    """
     value = config.get(key)
     if value is not None:
         if isinstance(value, dict):
@@ -35,12 +43,123 @@ def get_value(key):
         raise click.Exit(1)
 
 
+@config_cmd.command("set")
+@click.argument("key")
+@click.argument("value")
+@click.option("--json", "is_json", is_flag=True, help="Parse value as JSON")
+def set_value(key, value, is_json):
+    """Set a configuration value.
+
+    Examples:
+        mycli config set paths.newpath ~/Documents/new
+        mycli config set api_keys.newkey abc123
+        mycli config set --json ssh_hosts.newhost '{"host":"user@host","port":22}'
+    """
+    # Load current config
+    config_path = config._config_path
+    with open(config_path) as f:
+        data = json.load(f)
+
+    # Parse value
+    if is_json:
+        try:
+            parsed_value = json.loads(value)
+        except json.JSONDecodeError as e:
+            click.echo(f"Invalid JSON: {e}", err=True)
+            raise click.Exit(1)
+    else:
+        parsed_value = value
+
+    # Navigate to nested key
+    keys = key.split(".")
+    target = data
+    for k in keys[:-1]:
+        if k not in target:
+            target[k] = {}
+        target = target[k]
+
+    # Set value
+    target[keys[-1]] = parsed_value
+
+    # Save
+    with open(config_path, "w") as f:
+        json.dump(data, f, indent=2, ensure_ascii=False)
+        f.write("\n")
+
+    click.secho(f"Set {key} = {parsed_value}", fg="green")
+
+
+@config_cmd.command("delete")
+@click.argument("key")
+@click.option("--yes", "-y", is_flag=True, help="Skip confirmation")
+def delete_value(key, yes):
+    """Delete a configuration key.
+
+    Examples:
+        mycli config delete api_keys.oldkey
+        mycli config delete paths.oldpath
+    """
+    # Check if exists
+    if config.get(key) is None:
+        click.echo(f"Key not found: {key}", err=True)
+        raise click.Exit(1)
+
+    if not yes:
+        click.confirm(f"Delete '{key}'?", abort=True)
+
+    # Load current config
+    config_path = config._config_path
+    with open(config_path) as f:
+        data = json.load(f)
+
+    # Navigate and delete
+    keys = key.split(".")
+    target = data
+    for k in keys[:-1]:
+        if k not in target:
+            click.echo(f"Key not found: {key}", err=True)
+            raise click.Exit(1)
+        target = target[k]
+
+    if keys[-1] in target:
+        del target[keys[-1]]
+    else:
+        click.echo(f"Key not found: {key}", err=True)
+        raise click.Exit(1)
+
+    # Save
+    with open(config_path, "w") as f:
+        json.dump(data, f, indent=2, ensure_ascii=False)
+        f.write("\n")
+
+    click.secho(f"Deleted {key}", fg="green")
+
+
+@config_cmd.command("list")
+def list_keys():
+    """List all top-level configuration keys."""
+    config_path = config._config_path
+    with open(config_path) as f:
+        data = json.load(f)
+
+    click.secho("Configuration sections:", fg="cyan")
+    for key in sorted(data.keys()):
+        value = data[key]
+        type_str = type(value).__name__
+        if isinstance(value, dict):
+            count = len(value)
+            click.echo(f"  {key:20} ({type_str}, {count} items)")
+        elif isinstance(value, list):
+            click.echo(f"  {key:20} ({type_str}, {len(value)} items)")
+        else:
+            click.echo(f"  {key:20} ({type_str})")
+
+
 @config_cmd.command("paths")
 def list_paths():
     """List all configured paths."""
     paths = config.get_all_paths()
     max_len = max(len(name) for name in paths.keys())
-    from pathlib import Path
     for name, path in sorted(paths.items()):
         exists = "✓" if path.exists() else "✗"
         click.echo(f"{name:{max_len}}  [{exists}]  {path}")
@@ -56,3 +175,24 @@ def edit():
 def where():
     """Show configuration file location."""
     click.echo(config._config_path)
+
+
+@config_cmd.command("init")
+def init_config():
+    """Create initial config from example template."""
+    config_path = config._config_path
+    example_path = config_path.parent / "config.json.example"
+
+    if config_path.exists():
+        click.echo(f"Config already exists: {config_path}", err=True)
+        click.echo("Use 'mycli config edit' to modify it")
+        raise click.Exit(1)
+
+    if not example_path.exists():
+        click.echo(f"Example config not found: {example_path}", err=True)
+        raise click.Exit(1)
+
+    import shutil
+    shutil.copy(example_path, config_path)
+    click.secho(f"Created config from template: {config_path}", fg="green")
+    click.echo("Edit it to add your API keys and customize paths")