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/matrixcmd/help.go

@@ -0,0 +1,60 @@
+package matrixcmd
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+func NewHelpHandler(proc *Processor) Handler {
+	return NewHandler(Meta{
+		Name:        "help",
+		Description: "Show this help message.",
+	}, func(ctx *Context) {
+		ctx.Reply(formatHelp(proc, ctx))
+	})
+}
+
+func formatHelp(proc *Processor, ctx *Context) string {
+	var builder strings.Builder
+
+	switch {
+	case ctx.RoomID == ctx.User.ManagementRoom:
+		builder.WriteString(fmt.Sprintf("This is your management room: prefixing commands with `%s` is not required.\n", ctx.Bridge.Config.CommandPrefix))
+	case ctx.Portal != nil:
+		builder.WriteString(fmt.Sprintf("**This is a portal room**: you must always prefix commands with `%s`. Management commands will not be bridged.\n", ctx.Bridge.Config.CommandPrefix))
+	default:
+		builder.WriteString(fmt.Sprintf("This is not your management room: prefixing commands with `%s` is required.\n", ctx.Bridge.Config.CommandPrefix))
+	}
+
+	builder.WriteString("Parameters in [square brackets] are optional, while parameters in <angle brackets> are required.\n\n")
+	builder.WriteString("#### General\n")
+
+	handlers := proc.Handlers()
+	sort.SliceStable(handlers, func(i, j int) bool {
+		return handlers[i].Meta().Name < handlers[j].Meta().Name
+	})
+	for _, handler := range handlers {
+		meta := handler.Meta()
+		builder.WriteString("**")
+		builder.WriteString(meta.Name)
+		builder.WriteString("**")
+		if meta.Usage != "" {
+			builder.WriteByte(' ')
+			builder.WriteString(meta.Usage)
+		}
+		if meta.Description != "" {
+			builder.WriteString(" - ")
+			builder.WriteString(meta.Description)
+		}
+		builder.WriteByte('\n')
+	}
+
+	if extra := strings.TrimSpace(ctx.Processor.texts.AdditionalHelp); extra != "" {
+		builder.WriteByte('\n')
+		builder.WriteString(extra)
+		builder.WriteByte('\n')
+	}
+
+	return builder.String()
+}