feat(spells): allow spells to ignore spell resistance

SpellSpec gains spell_resistance: bool = True (JSON 'spell_resistance'). When false, _spell_delivery_blocked skips the targeted SR check and _apply_area_effect skips the per-creature SR check (threaded through the effect chain). Verified each imported spell against the local KB and set false on the 28 whose SRD block says 'Spell Resistance: no' (Acid Arrow, Flurry of Snowballs, Web, Darkness, Sanctuary, the Protection from X spells, etc.). Added no-SR targeted/area tests and a high-SR control in test_spell_resistance.py, and the README.

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

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

src/pf1e_simulator/combat.py

@@ -5478,6 +5478,7 @@ class CombatEngine:
         if (
             target is not None
             and not has_area
+            and spell.spell_resistance
             and not self._check_spell_resistance(caster, target)
         ):
             return True, False
@@ -5735,7 +5736,7 @@ class CombatEngine:
             maximize="Maximize Spell" in metamagic,
             dc=dc, center_pos=center_pos, save_type=spell.save,
             crit=spell_crit, ranged_touch=per_projectile_attack,
-            attack_penalty=attack_penalty,
+            attack_penalty=attack_penalty, spell_resistance=spell.spell_resistance,
         )
         save_str = _save_label(save_result)
         if target is None and center_pos is not None:
@@ -5794,6 +5795,7 @@ class CombatEngine:
         crit: bool = False,
         ranged_touch: bool = False,
         attack_penalty: int = 0,
+        spell_resistance: bool = True,
     ) -> list[str]:
         saved = save_result is not None and save_result.success
         return [
@@ -5803,6 +5805,7 @@ class CombatEngine:
                 empower=empower, maximize=maximize, saved=saved,
                 dc=dc, center_pos=center_pos, save_type=save_type,
                 crit=crit, ranged_touch=ranged_touch, attack_penalty=attack_penalty,
+                spell_resistance=spell_resistance,
             )
             for effect in effects
         ]
@@ -5825,6 +5828,7 @@ class CombatEngine:
         crit: bool = False,
         ranged_touch: bool = False,
         attack_penalty: int = 0,
+        spell_resistance: bool = True,
     ) -> str:
         if isinstance(effect, AreaEffect):
             return self._apply_area_effect(
@@ -5832,6 +5836,7 @@ class CombatEngine:
                 caster=caster, spell_name=spell_name, saved=saved,
                 empower=empower, maximize=maximize, dc=dc,
                 center_pos=center_pos, save_type=save_type,
+                spell_resistance=spell_resistance,
             )
         if isinstance(effect, SummonEffect):
             return self._apply_summon_effect(effect, caster, caster_live, spell_name)
@@ -6100,6 +6105,7 @@ class CombatEngine:
         dc: int = 15,
         center_pos: tuple[int, int] | None = None,
         save_type: SaveType = "none",
+        spell_resistance: bool = True,
     ) -> str:
         """Apply an area effect to all creatures within its template.
 
@@ -6125,7 +6131,7 @@ class CombatEngine:
         total_buffs = 0
 
         for affected_state in affected:
-            if not self._check_spell_resistance(caster, affected_state):
+            if spell_resistance and not self._check_spell_resistance(caster, affected_state):
                 continue
             creature_saved = self._area_save(
                 affected_state, target, effect, saved=saved, dc=dc,

src/pf1e_simulator/spells.py

@@ -238,6 +238,11 @@ class SpellSpec:
     # area/save-only spells keep this False.
     requires_ranged_touch: bool = False
     cast_time: CastTime = "standard"
+    # PF1e (CRB, Magic — Spell Resistance): most spells are subject to a
+    # target's SR, but the SRD stat block marks a handful "Spell Resistance:
+    # no" (Acid Arrow, Flurry of Snowballs, ...). False = skip the SR check
+    # entirely (targeted and per-creature in areas). Default True.
+    spell_resistance: bool = True
     effects: tuple[SpellEffect, ...] = ()
     description: str = ""
 
@@ -573,6 +578,7 @@ def load_spell(path: str | Path) -> SpellSpec:
         base_dc=_as_int(data.get("base_dc", 10)),
         requires_ranged_touch=bool(data.get("requires_ranged_touch", False)),
         cast_time=cast_time,
+        spell_resistance=bool(data.get("spell_resistance", True)),
         effects=effects,
         description=_as_str(data.get("description", "")),
     )