refactor: split the command dispatch out of main.go

Completes the restructuring started when main() became run() int. main.go goes
from 1217 lines to 130: global option handling, config loading, signal setup,
and a dispatch switch that delegates to one function per command.

The command bodies move to cmd_rip.go (url, file, id), cmd_search.go (search,
lastfm), cmd_config.go (config, database) and cmd_smoke.go (the developer smoke
commands), each taking (ctx, cfg, gopts, args) and returning an exit code.

They also stop reading the process global. Previously run() did

    os.Args = append([]string{os.Args[0], gopts.command}, gopts.commandArgs...)

and the arms then indexed back into os.Args[2:], os.Args[5:] and so on, so the
already-parsed options were round-tripped through os.Args. The arms now take
the parsed gopts.commandArgs directly, which is a uniform index shift of two
(os.Args[5:] -> args[3:], len(os.Args) < 5 -> len(args) < 3).

No behaviour change. Verified by running each command's argument validation and
help path against the built binary, plus the existing suite.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cmd/rip/cmd_config.go

@@ -0,0 +1,128 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"streamrip-go/internal/config"
+
+	"golang.org/x/term"
+)
+
+// Commands that inspect local state: config and database.
+
+func cmdConfig(_ context.Context, cfg *config.Config, _ globalOptions, args []string) int {
+	var err error
+	if len(args) < 1 {
+		printCommandHelp(os.Stdout, "config")
+		return 2
+	}
+	switch args[0] {
+	case "open":
+		vim := false
+		for _, arg := range args[1:] {
+			switch arg {
+			case "-v", "--vim":
+				vim = true
+			default:
+				fmt.Fprintf(os.Stderr, "option error: unknown option %q\n", arg)
+				return 2
+			}
+		}
+		fmt.Printf("opening file at %s\n", cfg.Path)
+		if err = openConfigInEditor(cfg.Path, vim); err != nil {
+			fmt.Fprintf(os.Stderr, "open config error: %v\n", err)
+			return 1
+		}
+	case "reset":
+		yes := false
+		for _, arg := range args[1:] {
+			switch arg {
+			case "-y", "--yes":
+				yes = true
+			default:
+				fmt.Fprintf(os.Stderr, "option error: unknown option %q\n", arg)
+				return 2
+			}
+		}
+		if !yes {
+			if !term.IsTerminal(int(os.Stdin.Fd())) {
+				fmt.Fprintln(os.Stderr, "reset requires --yes in non-interactive mode")
+				return 2
+			}
+			ok, askErr := promptYesNo(fmt.Sprintf("Are you sure you want to reset the config file at %s? [y/N]: ", cfg.Path))
+			if askErr != nil {
+				fmt.Fprintf(os.Stderr, "prompt error: %v\n", askErr)
+				return 1
+			}
+			if !ok {
+				fmt.Println("reset aborted")
+				return 0
+			}
+		}
+		def := config.DefaultConfigData()
+		// Separate copies: assigning the same value to both halves made
+		// File.Qobuz.Secrets and Session.Qobuz.Secrets share one backing
+		// array.
+		cfg.File = config.CloneConfigData(def)
+		cfg.Session = config.CloneConfigData(def)
+		if err = cfg.SaveFile(); err != nil {
+			fmt.Fprintf(os.Stderr, "reset config error: %v\n", err)
+			return 1
+		}
+		fmt.Printf("reset the config file at %s\n", cfg.Path)
+	case "path":
+		if len(args) > 1 {
+			fmt.Fprintf(os.Stderr, "option error: unexpected argument %q\n", args[1])
+			return 2
+		}
+		fmt.Printf("config path: '%s'\n", cfg.Path)
+	default:
+		fmt.Fprintf(os.Stderr, "unknown config command: %s\n", args[0])
+		return 2
+	}
+
+	return 0
+}
+
+func cmdDatabase(_ context.Context, cfg *config.Config, _ globalOptions, args []string) int {
+	if len(args) < 2 || args[0] != "browse" {
+		printCommandHelp(os.Stdout, "database")
+		return 2
+	}
+	table := strings.ToLower(strings.TrimSpace(args[1]))
+	switch table {
+	case "downloads":
+		rows, listErr := listDownloadsRows(cfg.Session.Database.DownloadsPath)
+		if listErr != nil {
+			fmt.Fprintf(os.Stderr, "database browse error: %v\n", listErr)
+			return 1
+		}
+		fmt.Println("downloads database")
+		fmt.Println("row  id")
+		for i, id := range rows {
+			fmt.Printf("%02d   %s\n", i, id)
+		}
+	case "failed":
+		rows, listErr := listFailedRows(cfg.Session.Database.FailedDownloadsPath)
+		if listErr != nil && isNoSuchTableErr(listErr) && cfg.Session.Database.FailedDownloadsPath != cfg.Session.Database.DownloadsPath {
+			rows, listErr = listFailedRows(cfg.Session.Database.DownloadsPath)
+		}
+		if listErr != nil {
+			fmt.Fprintf(os.Stderr, "database browse error: %v\n", listErr)
+			return 1
+		}
+		fmt.Println("failed downloads database")
+		fmt.Println("row  source   media_type   id")
+		for i, row := range rows {
+			fmt.Printf("%02d   %s   %s   %s\n", i, row.Source, row.MediaType, row.ID)
+		}
+	default:
+		fmt.Fprintf(os.Stderr, "invalid database %q. choose downloads or failed\n", table)
+		return 2
+	}
+
+	return 0
+}