fix(spells): backfill casting times for all imported spells

data/spells/deja_vu.json

@@ -5,6 +5,7 @@
   "range": "personal",
   "save": "none",
   "base_dc": 10,
+  "cast_time": "standard",
   "effects": [],
   "description": "A cantrip that lets you reroll one attack roll, saving throw, or skill check made in the past round (once per casting). Not modeled by the engine's action flow, so it carries no mechanical effect."
 }