Rename movement/world methods to idiomatic Go; remove all gotos

Refactor step 4. Renames (C breadcrumbs kept in doc comments):
doMove→moveHero, beTrapped→springTrap, rndmove→randomStep,
doRooms→digRooms, doPassages→digPassages, doMaze→digMaze,
chgStr→changeStrength, doRun→startRun, moveStuff→finishMove,
turnref→turnRefresh, moveMonst→moveMonster, doChase→chaseStep,
setOldch→setOldChar, cansee→canSee, roomin→roomIn, runto→runTo,
conn→connectRooms, putpass→putPassage, passnum→numberPassages,
numpass→numberPassage, rndPos→randomPos, rndRoom→randomRoom,
treasRoom→treasureRoom, accntMaze→accountMaze.

All goto/label flows are gone: moveHero uses a retry loop with the
PASSGO corner logic extracted into passageTurn; dispatch re-dispatches
via a loop; chaseStep re-checks via a loop; saveGame uses a labeled
prompt loop. Control flow and RNG call order are unchanged; suite
green.

game/monsters.go

@@ -37,7 +37,7 @@ func (g *RogueGame) newMonster(tp *Monster, typ byte, cp Coord) {
 	tp.Pos = cp
 	g.move(cp.Y, cp.X)
 	tp.OldCh = g.inch()
-	tp.Room = g.roomin(cp)
+	tp.Room = g.roomIn(cp)
 	g.Level.SetMonsterAt(cp.Y, cp.X, tp)
 	mp := &g.Monsters[tp.Type-'A']
 	tp.Stats.Lvl = mp.Stats.Lvl + levAdd
@@ -57,7 +57,7 @@ func (g *RogueGame) newMonster(tp *Monster, typ byte, cp Coord) {
 	tp.Pack = nil
 
 	if g.Player.IsWearing(RingAggravateMonsters) {
-		g.runto(cp)
+		g.runTo(cp)
 	}
 
 	if typ == 'X' {
@@ -92,7 +92,7 @@ func (g *RogueGame) wanderer() {
 	var cp Coord
 	for {
 		cp, _ = g.findFloor(true)
-		if g.roomin(cp) != g.Player.Room {
+		if g.roomIn(cp) != g.Player.Room {
 			break
 		}
 	}
@@ -111,7 +111,7 @@ func (g *RogueGame) wanderer() {
 		g.standend()
 	}
 
-	g.runto(tp.Pos)
+	g.runTo(tp.Pos)
 }
 
 // wakeMonster is what to do when the hero steps next to a monster