feat(rules): scale spell damage with caster level

DamageEffect gains optional scaling (1dX per N levels, capped) and scaling_flat (+X per N levels, capped) specs; effective_formula resolves them against the caster's level at cast time, so scaled dice flow through crits, energy resistance and metamagic like the base formula (CRB Magic - Caster Level). Loader rejects mismatched die types. Data: Fireball/Lightning Bolt 1d6/lvl max 10d6, Burning Hands 1d4/lvl max 5d4, Shocking Grasp 1d6/lvl max 5d6, Inflict Light Wounds +1/lvl max +5 (SRD-verified). Cure Light Wounds stays flat: its golden transcript pins 1d8+1 and HealEffect scaling is out of scope.

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

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

src/pf1e_simulator/combat.py

@@ -5783,9 +5783,13 @@ class CombatEngine:
         caster: CombatantState,
         crit: bool = False,
     ) -> str:
-        raw = effect.formula.roll(self._rng)
+        # PF1e (CRB, Magic — Caster Level): per-level spell damage is resolved
+        # against the caster's level at cast time; the scaled formula then
+        # flows through crits, energy resistance and metamagic unchanged.
+        formula = effect.effective_formula(caster.combatant.level)
+        raw = formula.roll(self._rng)
         if maximize:
-            raw = effect.formula.max_value()
+            raw = formula.max_value()
         if crit:
             # PF1e (CRB "Range — Touch"): a touch/ranged-touch spell that
             # deals damage threatens on a natural 20 and deals double damage