fix(rules): require a ranged touch attack for ray spells

PF1e CRB (Magic - Ranged Touch Attacks): spells delivered by ray require a
ranged touch attack (BAB + Dex vs touch AC, no range increment) to hit a
hostile target; a miss wastes the slot. SpellSpec gains requires_ranged_touch,
set on the 8 SRD-confirmed rays (Ray of Frost, Ray of Enfeeblement, Scorching
Ray, Acid Arrow, Acid Splash, Disrupt Undead, Shard of Chaos, Spear of Purity).
Magic Missile and area spells are unaffected. Simplification (documented): no
size modifier / Weapon Finesse on the roll.

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

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

data/spells/spear_of_purity.json

@@ -5,6 +5,7 @@
   "range": "close",
   "save": "will",
   "base_dc": 10,
+  "requires_ranged_touch": true,
   "cast_time": "standard",
   "effects": [],
   "description": "A spear of good energy (ranged touch attack): evil creatures take 1d8 per two caster levels (max 5d8); evil outsiders take 1d6 per caster level (max 10d6) and are blinded 1 round. A successful Will save halves the damage and negates the blind. Half damage to neutral creatures, no effect on good ones. No combat effect encoded: the engine has no alignment, so the alignment-gated damage cannot be represented."