feat(observation): expose spell cast time in the snapshot

The per-spell Observation dict gains the additive cast_time key: the
registry spell's budget code on a hit, "standard" on a miss (mirroring
the engine's resolver fallback), so an LLM policy can schedule casts
against the action budget it sees reported back.

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

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

README.md

@@ -977,7 +977,9 @@ Règles modélisées :
     spells (résumés enrichis du registre : name, level, school, range_ft,
     save, dc, summary, half_on_save, save_negates (E4), area {shape,
     radius_ft} | None (U7a : premier AreaEffect de niveau supérieur du sort,
-    gabarit de zone structuré, None si le sort n'a pas de zone)),
+    gabarit de zone structuré, None si le sort n'a pas de zone), cast_time
+    (code de temps d'incantation, « standard » pour un sort inconnu du
+    registre)),
     spell_resistance (int), resistances {type: montant}, immunities
     (tuple triée des types immunisés), sneak_dice (dés de précision disponibles :
     (niveau + 1) // 2 avec « Sneak Attack », sinon 0), engaged_in_melee (bool —

src/pf1e_simulator/combat.py

@@ -4574,6 +4574,7 @@ class CombatEngine:
                 "half_on_save": False,
                 "save_negates": False,
                 "area": None,
+                "cast_time": "standard",
             }
         half_on_save = _spell_half_on_save(spell)
         return {
@@ -4587,6 +4588,7 @@ class CombatEngine:
             "half_on_save": half_on_save,
             "save_negates": spell.save != "none" and not half_on_save,
             "area": _spell_area_dict(spell),
+            "cast_time": spell.cast_time,
         }
 
     def _cast_spell(

tests/test_observation_enriched.py

@@ -532,6 +532,7 @@ def test_observation_enriched_spells_unknown_graceful() -> None:
             "half_on_save": False,
             "save_negates": False,
             "area": None,
+            "cast_time": "standard",
         },
     )
 

tests/test_spell_area_snapshot.py

@@ -127,7 +127,7 @@ def test_area_snapshot_existing_keys_unchanged() -> None:
     """Given: a known Fireball snapshot dict
     When: all keys and values are checked
     Then: the nine pre-U7a keys are present with unchanged values, and the
-    exact key set is the old nine plus the additive "area"."""
+    exact key set is the old nine plus the additive "area" and "cast_time"."""
     s = _spell_dict_for(_FIREBALL, "Fireball")
     assert s["name"] == "Fireball"
     assert s["level"] == 3
@@ -140,6 +140,7 @@ def test_area_snapshot_existing_keys_unchanged() -> None:
     assert s["summary"] == "area 20ft"
     assert s["half_on_save"] is True
     assert s["save_negates"] is False
+    assert s["cast_time"] == "standard"
     assert set(s.keys()) == {
         "name",
         "level",
@@ -151,6 +152,7 @@ def test_area_snapshot_existing_keys_unchanged() -> None:
         "half_on_save",
         "save_negates",
         "area",
+        "cast_time",
     }