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/init.go

@@ -3,7 +3,49 @@ package game
 import "strings"
 
 // init.c — per-game randomization of item appearances and probability
-// tables. initPlayer arrives with the pack/items phase (it needs addPack).
+// tables, and the player roll-up.
+
+// initPlayer rolls her up (init.c init_player).
+func (g *RogueGame) initPlayer() {
+	p := &g.Player
+	p.MaxStats = initStats
+	p.Stats = p.MaxStats
+	p.FoodLeft = HungerTime
+	// Give him some food
+	obj := newObject()
+	obj.Type = Food
+	obj.Count = 1
+	g.addPack(obj, true)
+	// And his suit of armor
+	obj = newObject()
+	obj.Type = Armor
+	obj.Which = RingMail
+	obj.Arm = aClass[RingMail] - 1
+	obj.Flags.Set(IsKnow)
+	obj.Count = 1
+	p.CurArmor = obj
+	g.addPack(obj, true)
+	// Give him his weaponry.  First a mace.
+	obj = newObject()
+	g.initWeapon(obj, Mace)
+	obj.HPlus = 1
+	obj.DPlus = 1
+	obj.Flags.Set(IsKnow)
+	g.addPack(obj, true)
+	p.CurWeapon = obj
+	// Now a +1 bow
+	obj = newObject()
+	g.initWeapon(obj, Bow)
+	obj.HPlus = 1
+	obj.Flags.Set(IsKnow)
+	g.addPack(obj, true)
+	// Now some arrows
+	obj = newObject()
+	g.initWeapon(obj, Arrow)
+	obj.Count = g.rnd(15) + 25
+	obj.Flags.Set(IsKnow)
+	g.addPack(obj, true)
+}
 
 // initColors initializes the potion color scheme for this game
 // (init.c init_colors).