fix(rules): stop damage reduction from eating energy damage

PF1e (CRB Damage Reduction): "Damage reduction does not negate ...
energy damage dealt along with an attack." _resolve_hit_damage now
splits the post-crit total and applies DR only to the non-energy share
(physical dice + flat bonuses + precision dice); energy components are
reduced solely by the per-component energy resistance/immunity step.
DR-bypass semantics (multi-component "and" requires every component)
are unchanged. Pure-physical weapons keep bit-identical arithmetic and
the golden transcripts are untouched.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/pf1e_simulator/combat.py

@@ -36,7 +36,10 @@ Phase 0 documented deviations from PF1e (conventions):
   natural weapons in a single full attack are not modeled.
 - Natural 1 always misses; natural 20 always hits and threatens a crit.
 - A confirmed crit multiplies the total damage (dice + flat bonus) by crit_mult.
-- DR applies once, after crit multiplication; a single bypass type defeats
+- DR applies once, after crit multiplication, to the PHYSICAL portion of the
+  damage only (bludgeoning/piercing/slashing dice, flat bonuses and precision
+  dice) — energy damage dealt along with an attack is never reduced by DR
+  (CRB "Damage Reduction"); a single bypass type defeats
   DR; a multi-component "and" bypass (e.g. "bludgeoning and magic") requires
   EVERY component (PF1e "DR X/Y and Z" notation).
 - Death when negative hp reaches the Constitution score (hp <= -CON); PF1e
@@ -182,6 +185,9 @@ _FIGHT_DEFENSIVELY_AC_BONUS = 2  # PF1e: fighting defensively grants +2 dodge AC
 _FIGHT_DEFENSIVELY_ATTACK_PENALTY = -4  # PF1e: and -4 on attacks / crit confirms
 _SPELL_COMBAT_ATTACK_PENALTY = -2  # PF1e: magus Spell Combat melee attacks at -2
 _TOTAL_CONCEALMENT_PCT = 50  # PF1e: a blinded attacker's targets have total concealment
+# PF1e (CRB Damage Reduction): DR does not negate energy damage dealt along
+# with an attack — only these weapon damage types ride the DR path.
+_PHYSICAL_DAMAGE_TYPES = frozenset({"bludgeoning", "piercing", "slashing"})
 # PF1e confused d% table: 01-25 act normally, 26-50 babble, 51-75 hit self,
 # 76-100 attack the nearest creature
 _CONFUSED_ACT_NORMAL_MAX = 25
@@ -2442,7 +2448,19 @@ class CombatEngine:
         if crit:
             damage *= weapon.crit_mult
         damage += sneak_total
-        damage = self._apply_dr(damage, weapon, target)
+        # PF1e (CRB Damage Reduction): "Damage reduction does not negate ...
+        # energy damage dealt along with an attack" — DR reduces only the
+        # non-energy share of the damage (physical dice, flat bonuses and
+        # precision dice); energy components are cut solely by energy
+        # resistance/immunity in the per-component step below.
+        mult = weapon.crit_mult if crit else 1
+        energy_share = sum(
+            roll * mult
+            for comp, roll in zip(weapon.damage, rolls, strict=True)
+            if not _PHYSICAL_DAMAGE_TYPES.issuperset(comp.types)
+        )
+        physical = max(0, damage - energy_share)
+        damage = self._apply_dr(physical, weapon, target) + energy_share
         return crit, False, self._apply_energy_resistance_per_component(
             damage, weapon, rolls, crit=crit, target=target
         )
@@ -2633,10 +2651,11 @@ class CombatEngine:
         A component carrying several energy types uses the largest matching
         resistance (documented simplification: one die roll cannot be split
         across the listed types). Physical-only components match nothing in
-        the target's resistance/immunity maps and stay on the DR path, which
-        was applied to the lumped total just before this step (unchanged);
-        single-component weapons keep the exact arithmetic of the old
-        lumped-total path.
+        the target's resistance/immunity maps — they rode the DR path just
+        before this step, which reduces only the non-energy share of the
+        damage (CRB: DR does not negate energy damage dealt along with an
+        attack); single-component weapons keep the exact arithmetic of the
+        old lumped-total path.
         """
         mult = weapon.crit_mult if crit else 1
         for comp, roll in zip(weapon.damage, rolls, strict=True):