fix(rules): self-centered bursts for bless and bane - AreaEffect gains a data-driven 'centered_on_caster' flag (bless.json/bane.json set it per SRD bless.md '50-ft. burst, centered on the caster' and bane.md 'centered on you'); the burst origin is the caster's square regardless of the resolved target or a U7b target_pos, and with no chosen origin there is no primary save - every creature in the area rolls its own (mirror of the point-cast path); snapshot area key exposes centered_on_caster; golden transcript unchanged; +6 tests

data/spells/bane.json

@@ -11,6 +11,7 @@
       "type": "area",
       "radius_ft": 50,
       "targets": "enemies",
+      "centered_on_caster": true,
       "save_for_half": false,
       "effects": [
         {

data/spells/bless.json

@@ -11,6 +11,7 @@
       "type": "area",
       "radius_ft": 50,
       "targets": "allies",
+      "centered_on_caster": true,
       "save_for_half": false,
       "effects": [
         {