Give every NPC a race and class, resolved at spawn time

NPCs can now optionally specify race and class in their TOML. When
omitted, race is randomly selected from non-hidden races and class is
determined by the race's default_class or picked randomly from
compatible non-hidden classes. Race/class are re-rolled on each
respawn for NPCs without fixed values, so killing the barkeep may
bring back a different race next time.

New hidden content (excluded from character creation):
- Beast race: for animals (rats, etc.) with feral stats and no
  equipment slots
- Peasant class: weak default for humanoid NPCs
- Creature class: default for beasts/animals

Existing races gain default_class fields (humanoids → peasant,
beast → creature, dragon → random compatible). Look and examine
commands now display NPC race and class.

Made-with: Cursor

world/races/beast.toml

@@ -0,0 +1,40 @@
+name = "Beast"
+description = "A wild creature driven by instinct and survival."
+metarace = "animal"
+hidden = true
+default_class = "class:creature"
+
+[stats]
+strength = 0
+dexterity = 1
+constitution = 1
+intelligence = -4
+wisdom = -2
+perception = 2
+charisma = -3
+
+[body]
+size = "small"
+weight = 10
+slots = []
+
+[natural]
+armor = 0
+
+[natural.attacks.bite]
+damage = 4
+type = "physical"
+
+traits = ["feral", "keen_senses"]
+disadvantages = ["no_speech", "no_equipment"]
+
+[regen]
+hp = 1.2
+mana = 0.0
+endurance = 1.5
+
+[misc]
+lifespan = 15
+diet = "omnivore"
+xp_rate = 1.0
+vision = ["normal", "low_light"]