go: port command loop, save/restore, tcell terminal, and the binary

- command.c in full: the command dispatcher with repeat counts, run
  prefixes, ctrl-run door-stop mode, fight-to-death targeting, and all
  wizard debug commands; search, help, identify, d_level/u_level, call,
  current
- main.c completed: Run()/playit() with the C double ROGUEOPTS parse;
  exit()-anywhere becomes a gameEnd panic recovered in Run
- save.c + state.c: gob SaveState snapshot with explicit pointer-to-
  index fixups for equipment, monster rooms, and chase targets (the
  rs_fix_thing role); save file deleted on restore as in C; SIGHUP/
  SIGTERM autosave hook
- wizard.c completed (create_obj, show_map), passages.c add_pass
- term/: tcell/v2 Terminal — the one third-party dependency — replacing
  curses and mdport's 900-line key decoder; shell escape via suspend
- cmd/rogue: flags -s/-d, SEED (wizard), ROGUEOPTS, ROGUE_WIZARD

Tests: full scripted sessions through Run (quit, descend stairs,
3200-move crash sweep, save-command round trip). Notable fixes found
by tests: gob silently drops embedded fields of unexported types, and
--More-- prompts swallow space-free input scripts.

cmd/rogue/main.go

@@ -0,0 +1,101 @@
+// Command rogue is the Go port of Rogue 5.4.4: Exploring the Dungeons of
+// Doom. It is a faithful function-by-function port of the classic C game;
+// see ARCHITECTURE.md at the repository root.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/signal"
+	"os/user"
+	"strconv"
+	"syscall"
+	"time"
+
+	"sneak.berlin/go/rogue/game"
+	"sneak.berlin/go/rogue/term"
+)
+
+func main() {
+	scores := flag.Bool("s", false, "print the scoreboard and exit")
+	deathDemo := flag.Bool("d", false, "die a random death (demo)")
+	flag.Parse()
+
+	home, _ := os.UserHomeDir()
+
+	// get options from environment (main.c)
+	rogueOpts := os.Getenv("ROGUEOPTS")
+	name := ""
+	if u, err := user.Current(); err == nil {
+		name = u.Username
+	}
+
+	wizard := os.Getenv("ROGUE_WIZARD") != ""
+	// dungeon number: SEED for reproducible dungeons (wizard mode in C),
+	// else time+pid
+	var seed int32
+	if env := os.Getenv("SEED"); env != "" && wizard {
+		n, _ := strconv.Atoi(env)
+		seed = int32(n)
+	} else {
+		seed = int32(time.Now().Unix()) + int32(os.Getpid())
+	}
+
+	cfg := game.Config{
+		Seed:      seed,
+		Name:      name,
+		RogueOpts: rogueOpts,
+		Home:      home,
+		ScorePath: home + "/.rogue.scores",
+		Wizard:    wizard,
+	}
+
+	if *scores {
+		g := game.NewGame(cfg)
+		g.ShowScores()
+		return
+	}
+
+	t, err := term.New()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	defer t.Fini()
+	cfg.Term = t
+
+	var g *game.RogueGame
+	if args := flag.Args(); len(args) == 1 && !*deathDemo {
+		// restore a saved game
+		g, err = game.Restore(args[0], cfg)
+		if err != nil {
+			t.Fini()
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+	} else {
+		g = game.NewGame(cfg)
+	}
+
+	if *deathDemo {
+		g.DeathDemo()
+		return
+	}
+
+	// SIGHUP/SIGTERM autosave (save.c auto_save)
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, syscall.SIGHUP, syscall.SIGTERM)
+	go func() {
+		<-sig
+		g.AutoSave()
+		t.Fini()
+		os.Exit(0)
+	}()
+
+	if err := g.Run(); err != nil {
+		t.Fini()
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}