feat: add config file support to CLI

- Add ~/.webber/config.toml for persistent settings
- Support api.url, api.key, cli.mode, cli.stream, history.file
- Environment variables override config file values
- Add 'config' command to show settings and init config file
- Update all commands to use config defaults

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

webber-cli/webber_cli/config.py

@@ -0,0 +1,152 @@
+"""
+Configuration management for Webber CLI.
+
+Loads settings from ~/.webber/config.toml with environment variable overrides.
+"""
+import os
+import tomllib
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any
+
+
+# Config directory and file paths
+CONFIG_DIR = Path.home() / ".webber"
+CONFIG_FILE = CONFIG_DIR / "config.toml"
+
+# Default configuration template
+DEFAULT_CONFIG = """\
+# Webber CLI Configuration
+# https://github.com/jpmschweitzer/webber
+
+[api]
+# API server URL (dev: 8095, prod: 8086)
+url = "http://localhost:8095"
+
+# API key for authentication (optional for dev mode)
+# key = "your-api-key"
+
+[cli]
+# Default permission mode: default, plan, auto_accept
+mode = "default"
+
+# Enable streaming by default
+stream = true
+
+[history]
+# Command history file location
+file = "~/.webber_history"
+"""
+
+
+@dataclass
+class ApiConfig:
+    """API connection settings."""
+    url: str = "http://localhost:8095"
+    key: str | None = None
+
+
+@dataclass
+class CliConfig:
+    """CLI behavior settings."""
+    mode: str = "default"
+    stream: bool = True
+
+
+@dataclass
+class HistoryConfig:
+    """History settings."""
+    file: str = "~/.webber_history"
+
+
+@dataclass
+class Config:
+    """Complete configuration."""
+    api: ApiConfig = field(default_factory=ApiConfig)
+    cli: CliConfig = field(default_factory=CliConfig)
+    history: HistoryConfig = field(default_factory=HistoryConfig)
+
+
+def load_config() -> Config:
+    """
+    Load configuration from file with environment variable overrides.
+
+    Priority (highest to lowest):
+    1. Environment variables (WEBBER_API_URL, WEBBER_API_KEY, WEBBER_MODE)
+    2. Config file (~/.webber/config.toml)
+    3. Built-in defaults
+
+    Returns:
+        Config object with merged settings
+    """
+    config = Config()
+
+    # Load from file if exists
+    if CONFIG_FILE.exists():
+        try:
+            with open(CONFIG_FILE, "rb") as f:
+                data = tomllib.load(f)
+            config = _parse_config(data)
+        except Exception:
+            # If config file is invalid, use defaults
+            pass
+
+    # Apply environment variable overrides
+    if url := os.environ.get("WEBBER_API_URL"):
+        config.api.url = url
+    if key := os.environ.get("WEBBER_API_KEY"):
+        config.api.key = key
+    if mode := os.environ.get("WEBBER_MODE"):
+        config.cli.mode = mode
+
+    return config
+
+
+def _parse_config(data: dict[str, Any]) -> Config:
+    """Parse config dict into Config object."""
+    config = Config()
+
+    if api := data.get("api"):
+        config.api.url = api.get("url", config.api.url)
+        config.api.key = api.get("key", config.api.key)
+
+    if cli := data.get("cli"):
+        config.cli.mode = cli.get("mode", config.cli.mode)
+        config.cli.stream = cli.get("stream", config.cli.stream)
+
+    if history := data.get("history"):
+        config.history.file = history.get("file", config.history.file)
+
+    return config
+
+
+def init_config() -> Path:
+    """
+    Initialize config directory and file with defaults.
+
+    Returns:
+        Path to the created config file
+    """
+    CONFIG_DIR.mkdir(parents=True, exist_ok=True)
+
+    if not CONFIG_FILE.exists():
+        CONFIG_FILE.write_text(DEFAULT_CONFIG)
+
+    return CONFIG_FILE
+
+
+def get_config_path() -> Path | None:
+    """Get path to config file if it exists."""
+    return CONFIG_FILE if CONFIG_FILE.exists() else None
+
+
+# Module-level cached config
+_config: Config | None = None
+
+
+def get_config() -> Config:
+    """Get cached config, loading if necessary."""
+    global _config
+    if _config is None:
+        _config = load_config()
+    return _config