go: port dungeon generation, items base, pack, and monster creation

rooms.c, passages.c, new_level.c ported in full: room/maze layout,
corridor spanning tree with extra connections, passage numbering flood
fill, trap/stairs/object placement, treasure rooms. Careful RNG-call
ordering throughout keeps generation seed-faithful to C.

Supporting subsystems this depends on, also ported:
- screen.go: curses replaced by in-memory Window cell buffers behind a
  Terminal interface (tcell arrives with the UI phase; tests run headless)
- io.go: msg/addmsg/endmsg message-line protocol, status line, step_ok
- pack.c in full (add_pack sorting/stacking walk, get_item, inventory)
- things.c in full (inv_name, new_thing, discovery lists, pagination)
- monsters.c in full; chase.c navigation half (roomin/cansee/see_monst/
  find_dest/runto/set_oldch); rings.c, armor.c in full
- weapons.c/sticks.c creation half (init_weapon, fix_stick, num)
- misc.c look() display update, eat, level-up, direction input
- daemons.c callbacks except stomach (needs death()) and the runners
  chase driver (combat phase)
- init.c init_player with the starting kit

Tests: level invariants across seeds, determinism, 30-depth sweep.

game/fight.go

@@ -0,0 +1,28 @@
+package game
+
+// fight.c — combat. setMname arrives first (monster wake-ups need it); the
+// combat resolution functions come with the combat phase.
+
+// setMname returns the monster name for the given monster (fight.c
+// set_mname).
+func (g *RogueGame) setMname(tp *Monster) string {
+	if !g.seeMonst(tp) && !g.Player.On(SeeMonst) {
+		if g.Options.Terse {
+			return "it"
+		}
+		return "something"
+	}
+	var mname string
+	if g.Player.On(IsHalu) {
+		ch := int(g.mvinch(tp.Pos.Y, tp.Pos.X))
+		if !isUpper(byte(ch)) {
+			ch = g.rnd(26)
+		} else {
+			ch -= 'A'
+		}
+		mname = monsterTable[ch].Name
+	} else {
+		mname = monsterTable[tp.Type-'A'].Name
+	}
+	return "the " + mname
+}