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/grasp.json

@@ -6,6 +6,7 @@
   "save": "none",
   "base_dc": 10,
   "cast_time": "immediate",
+  "spell_resistance": false,
   "effects": [],
   "description": "A cantrip cast as an immediate action when you fail a Climb check and would fall: you immediately retry the Climb check at a -2 penalty (increasing by 2 per successive use in the same situation); on success you don't fall. Climbing is not modeled by the engine, so the spell has no mechanical effects here."
 }