feat(state): CharacterSheet — store the inputs, derive the rest

Stores only what was rolled or chosen, plus current hp/mp (the only two numbers
that genuinely mutate). Everything else is a function, so no derived number can
drift from its inputs and M5's level curve is a function change, not a migration.

LCK has no row and no accessor here — §7 holds by construction.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QYa9u7Kdxv5gX4AnwWexy8

client/scripts/state/character_sheet.gd

@@ -0,0 +1,94 @@
+class_name CharacterSheet
+extends RefCounted
+## The character, as state (§2). STORES only what was rolled or chosen, plus the two
+## numbers that genuinely mutate in play (current hp/mp). Everything else is DERIVED —
+## so a derived number can never drift from the inputs that produced it, and M5's level
+## curve becomes a function change rather than a stored-field migration.
+##
+## LCK IS NOT HERE, and there is no accessor for it. It lives in GameState.luck: no
+## save, no skill, no row (§7). That holds by construction, not by discipline.
+
+const PROF_BONUS_L1 := 2
+
+# --- stored: rolled, chosen, or genuinely mutable -------------------------------
+var attributes: Dictionary = {}   # {str,dex,con,fth,mag} — final, post-spend
+var race_id: String = ""
+var calling_id: String = ""
+var level: int = 1
+var skills: Array = []            # chosen + race-granted + the human's bonus pick
+var bonus_skill: String = ""      # human only; also present in `skills`
+var hp: int = 0                   # CURRENT hp — combat writes this
+var mp: int = 0                   # CURRENT mp
+
+
+# --- derived: functions, never stored -------------------------------------------
+func modifier(stat: String) -> int:
+	return Attributes.modifier(int(attributes.get(stat, 10)))
+
+
+func prof_bonus() -> int:
+	return PROF_BONUS_L1  # the level curve is M5's; creation is L1
+
+
+func max_hp() -> int:
+	return Callings.hit_die(calling_id) + modifier("con")
+
+
+func max_mp() -> int:
+	# TUNABLE — M5 owns the real MP curve (races-and-classes spec §6 defers it).
+	# The SHAPE is what M4-b needs to draw a bar: martials have no pool at all; a
+	# caster's scales off the casting stat, with a floor so a bad roll still casts.
+	if not Callings.is_caster(calling_id):
+		return 0
+	return maxi(4, 4 + 4 * modifier(Callings.casting_stat(calling_id)))
+
+
+func ac() -> int:
+	return 10 + modifier("dex")  # armor is an item -> M7
+
+
+func initiative() -> int:
+	return modifier("dex")
+
+
+func is_proficient(skill: String) -> bool:
+	return skill in skills
+
+
+func save(stat: String) -> int:
+	var v := modifier(stat)
+	if stat in Callings.saves(calling_id):
+		v += prof_bonus()
+	v += Races.save_bonus(race_id)  # human's +1 to all five
+	return v
+
+
+func poison_save_bonus() -> int:
+	# Situational (vs poison + the affliction track) — deliberately NOT folded into
+	# save("con"), because a conditional inside a flat number is a sheet that lies.
+	return Races.poison_save_bonus(race_id)
+
+
+func skill_bonus(skill: String) -> int:
+	var v := modifier(Skills.attribute(skill))
+	if is_proficient(skill):
+		v += prof_bonus()
+	return v
+
+
+func spell_dc() -> int:
+	if not Callings.is_caster(calling_id):
+		return 0
+	return 8 + prof_bonus() + modifier(Callings.casting_stat(calling_id))
+
+
+func has_nightsight() -> bool:
+	return Races.flag(race_id, "nightsight")
+
+
+func has_claws() -> bool:
+	return Races.flag(race_id, "claws")
+
+
+func has_keen_scent() -> bool:
+	return Races.flag(race_id, "keen_scent")

client/scripts/state/character_sheet.gd.uid

@@ -0,0 +1 @@
+uid://mofimtmsxuui

client/tests/unit/test_character_sheet.gd

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+extends "res://addons/gut/test.gd"
+
+const CharacterSheet = preload("res://scripts/state/character_sheet.gd")
+
+
+func _sheet(race := "human", calling := "sellsword", attrs := {}) -> CharacterSheet:
+	var s = CharacterSheet.new()
+	s.race_id = race
+	s.calling_id = calling
+	s.attributes = {"str": 14, "dex": 12, "con": 14, "fth": 10, "mag": 8}
+	for k in attrs:
+		s.attributes[k] = attrs[k]
+	return s
+
+
+func test_max_hp_is_hit_die_plus_con_mod():
+	var s = _sheet("human", "reaver")          # d12, CON 14 -> +2
+	assert_eq(s.max_hp(), 14)
+	var frail = _sheet("human", "hedge_mage", {"con": 8})   # d6, CON 8 -> -1
+	assert_eq(frail.max_hp(), 5)
+
+
+func test_ac_is_ten_plus_dex():
+	assert_eq(_sheet().ac(), 11)               # DEX 12 -> +1. Armor is an item (M7).
+
+
+func test_initiative_is_dex():
+	assert_eq(_sheet().initiative(), 1)
+
+
+func test_save_picks_up_calling_proficiency():
+	var s = _sheet("elf", "sellsword")         # saves STR, CON; prof +2
+	assert_eq(s.save("str"), 4)                # STR 14 -> +2, +2 prof
+	assert_eq(s.save("dex"), 1)                # DEX 12 -> +1, not proficient
+
+
+func test_human_plus_one_lands_on_all_five_saves():
+	var human = _sheet("human", "sellsword")
+	var elf = _sheet("elf", "sellsword")
+	for stat in ["str", "dex", "con", "fth", "mag"]:
+		assert_eq(human.save(stat), elf.save(stat) + 1, "human +1 on %s" % stat)
+
+
+func test_dwarf_poison_bonus_is_not_in_the_con_save():
+	var dwarf = _sheet("dwarf", "sellsword")
+	var elf = _sheet("elf", "sellsword")
+	assert_eq(dwarf.save("con"), elf.save("con"), "the +2 is situational, not a flat CON save")
+	assert_eq(dwarf.poison_save_bonus(), 2)
+	assert_eq(elf.poison_save_bonus(), 0)
+
+
+func test_skill_bonus_uses_the_governing_attribute():
+	var s = _sheet()                            # STR 14 -> +2
+	assert_eq(s.skill_bonus("athletics"), 2, "not proficient: attribute only")
+	s.skills = ["athletics"]
+	assert_eq(s.skill_bonus("athletics"), 4, "proficient: +2 prof")
+
+
+func test_bonus_skill_confers_proficiency_via_the_skills_list():
+	var s = _sheet()
+	s.skills = ["athletics", "endurance"]       # Task 5 appends the human's pick here
+	s.bonus_skill = "endurance"
+	assert_true(s.is_proficient("endurance"))
+	assert_false(s.is_proficient("stealth"))
+
+
+func test_martials_have_no_mp_and_no_spell_dc():
+	var s = _sheet("human", "sellsword")
+	assert_eq(s.max_mp(), 0)
+	assert_eq(s.spell_dc(), 0)
+
+
+func test_casters_have_mp_and_a_spell_dc():
+	var s = _sheet("human", "bonesetter", {"fth": 16})   # FTH 16 -> +3
+	assert_true(s.max_mp() > 0, "a caster has a pool")
+	assert_eq(s.spell_dc(), 13)                          # 8 + 2 prof + 3
+
+
+func test_race_flags_are_exposed():
+	assert_true(_sheet("elf").has_nightsight())
+	assert_false(_sheet("human").has_nightsight())
+	assert_true(_sheet("beastfolk").has_claws())
+	assert_true(_sheet("beastfolk").has_keen_scent())
+	assert_false(_sheet("dwarf").has_claws())
+
+
+func test_luck_is_nowhere_on_the_sheet():
+	# §7: LCK has no save, no skill, no row, no accessor. It lives in GameState.
+	var s = _sheet()
+	assert_false("lck" in s.attributes, "LCK is never an attribute row")
+	assert_false(s.has_method("luck"), "the sheet must not expose Luck")

client/tests/unit/test_character_sheet.gd.uid

@@ -0,0 +1 @@
+uid://dgi5hu3y2fg2u