Add Arrtrix runtime, config, onboarding, and webhook support

- Implement runtime package for bridge startup, config loading, and env
  overrides
- Add onboarding package for management room welcome messages
- Add matrixcmd package for command processing and help
- Add webhook package with Radarr webhook support and validation
- Extend connector config for webhooks and validation
- Update default config and example config for new options
- Add tests for new packages and config validation
- Change database type default to sqlite3-fk-wal

packages/arrtrix/pkg/config/config.go

@@ -0,0 +1,61 @@
+package config
+
+import (
+	"go.mau.fi/util/dbutil"
+	"go.mau.fi/zeroconfig"
+	"gopkg.in/yaml.v3"
+
+	"maunium.net/go/mautrix/bridgev2/bridgeconfig"
+)
+
+type Config struct {
+	Network yaml.Node `yaml:"network"`
+
+	Bridge     bridgeconfig.BridgeConfig     `yaml:"bridge"`
+	Database   dbutil.Config                 `yaml:"database"`
+	Homeserver bridgeconfig.HomeserverConfig `yaml:"homeserver"`
+	AppService bridgeconfig.AppserviceConfig `yaml:"appservice"`
+	Logging    zeroconfig.Config             `yaml:"logging"`
+
+	EnvConfigPrefix string                           `yaml:"env_config_prefix"`
+	ManagementTexts bridgeconfig.ManagementRoomTexts `yaml:"management_room_texts"`
+}
+
+func Load(data []byte) (*Config, error) {
+	var cfg Config
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return nil, err
+	}
+	cfg.applyDefaults()
+	return &cfg, nil
+}
+
+func (c *Config) applyDefaults() {
+	if c.Homeserver.Software == "" {
+		c.Homeserver.Software = bridgeconfig.SoftwareStandard
+	}
+}
+
+func (c *Config) Compile() bridgeconfig.Config {
+	return bridgeconfig.Config{
+		Network:             c.Network,
+		Bridge:              c.Bridge,
+		Database:            c.Database,
+		Homeserver:          c.Homeserver,
+		AppService:          c.AppService,
+		Logging:             c.Logging,
+		EnvConfigPrefix:     c.EnvConfigPrefix,
+		ManagementRoomTexts: c.ManagementTexts,
+		Matrix: bridgeconfig.MatrixConfig{
+			MessageStatusEvents: false,
+			DeliveryReceipts:    false,
+			MessageErrorNotices: true,
+			SyncDirectChatList:  false,
+			FederateRooms:       true,
+		},
+		DoublePuppet: bridgeconfig.DoublePuppetConfig{
+			Servers: map[string]string{},
+			Secrets: map[string]string{},
+		},
+	}
+}