feat(spells): allow spells to ignore spell resistance

SpellSpec gains spell_resistance: bool = True (JSON 'spell_resistance'). When false, _spell_delivery_blocked skips the targeted SR check and _apply_area_effect skips the per-creature SR check (threaded through the effect chain). Verified each imported spell against the local KB and set false on the 28 whose SRD block says 'Spell Resistance: no' (Acid Arrow, Flurry of Snowballs, Web, Darkness, Sanctuary, the Protection from X spells, etc.). Added no-SR targeted/area tests and a high-SR control in test_spell_resistance.py, and the README.

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

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

data/spells/sanctuary.json

@@ -6,6 +6,7 @@
   "save": "will",
   "base_dc": 10,
   "cast_time": "standard",
+  "spell_resistance": false,
   "effects": [],
   "description": "You ward a creature against attacks for 1 round/level: any opponent attempting to directly attack the warded creature must succeed on a Will save or be unable to follow through with that attack and cannot directly attack the subject for the duration. The subject cannot attack without ending the spell. Will negates. No combat effect encoded: the engine has no attack-refusal-by-save mechanic, so the protection cannot be represented."
 }