Rename constants to descriptive names (refactor step 1)

Pure rename, no behavior change; the full suite (RNG goldens,
generation invariants, scripted sessions, save round trip) is
unchanged and green.

- Creature flags: IsHuh→Confused, IsHalu→Hallucinating,
  CanHuh→CanConfuse, CanSee→CanSeeInvisible, IsRun→Awake,
  SeeMonst→SenseMonsters, IsCanc→Cancelled, IsLevit→Levitating,
  IsBlind/IsGreed/IsHaste/IsTarget/IsHeld/IsInvis/IsMean/IsRegen/
  IsFly/IsSlow → Blind/Greedy/Hasted/Targeted/Held/Invisible/Mean/
  Regenerates/Flying/Slowed, IsFound→Found
- Object flags: IsCursed→Cursed, IsKnow→Known, IsMissl→Missile,
  IsMany→Stackable, ObjIsFound→WasFound, IsProt→Protected
- Room flags: IsDark/IsGone/IsMaze → Dark/Gone/Maze; place flags:
  FPass→FPassage, FPNum→FPassNum, FTMask→FTrapMask
- Trap types: TDoor→TrapDoor ... TMyst→TrapMystery
- Item subtypes: P*→Potion* (PLSD→PotionLSD, PMFind→
  PotionDetectMonsters, ...), S*→Scroll* (SIDRorS→
  ScrollIdentifyRingOrStick, ...), R*→Ring* (RAddHit→RingDexterity,
  RNop→RingAdornment, ...), Ws*→Wand* (WsElect→WandLightning, ...),
  weapons (TwoSword→WeaponTwoHandedSword, Shiraken→WeaponShuriken,
  ...), armor (RingMail→ArmorRingMail, ...)
- Counts: Max{Potions,Scrolls,Rings,Sticks,Weapons,Armors} →
  Num{Potion,Scroll,Ring,Wand,Weapon,Armor}Types; NTraps→NumTrapTypes
- Level.NTraps field → TrapCount (also in the save snapshot)
- Original C constant names preserved as comment breadcrumbs in
  types.go so the lineage stays greppable

TODO.md: step 1 moved to Completed, step 2 (typed kinds) promoted to
Next Step.

game/newlevel.go

@@ -12,7 +12,7 @@ const (
 // NewLevel digs and draws a new level (new_level.c new_level).
 func (g *RogueGame) NewLevel() {
 	p := &g.Player
-	p.Flags.Clear(IsHeld) // unhold when you go down just in case
+	p.Flags.Clear(Held) // unhold when you go down just in case
 	if g.Depth > g.MaxDepth {
 		g.MaxDepth = g.Depth
 	}
@@ -31,11 +31,11 @@ func (g *RogueGame) NewLevel() {
 	g.putThings() // Place objects (if any)
 	// Place the traps
 	if g.rnd(10) < g.Depth {
-		g.Level.NTraps = g.rnd(g.Depth/4) + 1
-		if g.Level.NTraps > MaxTraps {
-			g.Level.NTraps = MaxTraps
+		g.Level.TrapCount = g.rnd(g.Depth/4) + 1
+		if g.Level.TrapCount > MaxTraps {
+			g.Level.TrapCount = MaxTraps
 		}
-		for i := g.Level.NTraps; i > 0; i-- {
+		for i := g.Level.TrapCount; i > 0; i-- {
 			// not only wouldn't it be NICE to have traps in mazes (not
 			// that we care about being nice), since the trap number is
 			// stored where the passage number is, we can't actually do it.
@@ -48,7 +48,7 @@ func (g *RogueGame) NewLevel() {
 			}
 			sp := g.Level.FlagsAt(stairs.Y, stairs.X)
 			sp.Clear(FReal)
-			*sp |= PlaceFlags(g.rnd(NTraps))
+			*sp |= PlaceFlags(g.rnd(NumTrapTypes))
 		}
 	}
 	// Place the staircase down.
@@ -65,10 +65,10 @@ func (g *RogueGame) NewLevel() {
 	p.Pos = hero
 	g.enterRoom(hero)
 	g.mvaddch(hero.Y, hero.X, PlayerCh)
-	if p.On(SeeMonst) {
+	if p.On(SenseMonsters) {
 		g.turnSee(false)
 	}
-	if p.On(IsHalu) {
+	if p.On(Hallucinating) {
 		g.visuals(0)
 	}
 }
@@ -77,7 +77,7 @@ func (g *RogueGame) NewLevel() {
 func (g *RogueGame) rndRoom() int {
 	for {
 		rm := g.rnd(MaxRooms)
-		if !g.Level.Rooms[rm].Flags.Has(IsGone) {
+		if !g.Level.Rooms[rm].Flags.Has(Gone) {
 			return rm
 		}
 	}
@@ -151,7 +151,7 @@ func (g *RogueGame) treasRoom() {
 		if mp, ok := g.findFloorIn(rp, maxTries, true); ok {
 			tp := &Monster{}
 			g.newMonster(tp, g.randMonster(false), mp)
-			tp.Flags.Set(IsMean) // no sloughers in THIS room
+			tp.Flags.Set(Mean) // no sloughers in THIS room
 			g.givePack(tp)
 		}
 	}