Minimize D&D spell extraction contracts

internal/modules/dnd/codec/spells/testdata/dnd_spells.v1.json

@@ -3,8 +3,6 @@
     {
       "caster": "Aria",
       "spell": "Cure Wounds",
-      "effect": "Heals an injured ally.",
-      "narrative_description": "Aria restores the fighter after the fight.",
       "source_refs": [
         {
           "source_id": "session-alpha",
@@ -16,8 +14,6 @@
     {
       "caster": "Borin",
       "spell": "Fire Bolt",
-      "effect": "Scorches the wight.",
-      "narrative_description": "Borin hurls fire at the wight.",
       "source_refs": [
         {
           "source_id": "session-alpha",