fix(rules): shield of faith grants its SRD deflection AC buff (+2, +1 per six caster levels, max +5) via a new BuffEffect flat scaling

src/pf1e_simulator/spells.py

@@ -213,8 +213,17 @@ class HealEffect:
 
 @dataclass(frozen=True)
 class BuffEffect:
+    """Transient stat modifiers (PF1e buff spells).
+
+    ``scaling_flat`` (SRD shield of faith "+2 deflection, +1 per six caster
+    levels (maximum +5)", divine favor "+1 per three caster levels (maximum
+    +3)") adds the resolved flat bonus to EVERY modifier's value at cast
+    time, mirroring ``DamageEffect.effective_formula``'s flat scaling.
+    """
+
     modifiers: tuple[StatModifier, ...]
     duration_rounds: int
+    scaling_flat: DamageFlatScaling | None = None
 
 
 @dataclass(frozen=True)
@@ -611,9 +620,12 @@ def _parse_heal_effect(effect: dict[str, Json]) -> HealEffect:
 
 
 def _parse_buff_effect(effect: dict[str, Json]) -> BuffEffect:
+    flat_raw = effect.get("scaling_flat")
+    scaling_flat = None if flat_raw is None else _parse_flat_scaling(flat_raw)
     return BuffEffect(
         modifiers=tuple(_parse_modifier(m) for m in _as_list(effect["modifiers"])),
         duration_rounds=_as_int(effect.get("duration_rounds", 0)),
+        scaling_flat=scaling_flat,
     )