feat(rules): the race, calling, skill and attribute tables

Mechanics are rules and live in code, beside Luck and Currency. The skill pools
are new — the races/classes spec said only 'the stat-appropriate slice' and never
enumerated them; each pool is larger than its pick count so the choice is real.

The dwarf's +2 vs poison is exposed separately from save() rather than folded
into it: baking a conditional into a flat number is how a sheet starts lying.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QYa9u7Kdxv5gX4AnwWexy8

client/scripts/rules/skills.gd

@@ -0,0 +1,28 @@
+class_name Skills
+extends RefCounted
+## The 9 skills and the attribute each is governed by (races-and-classes spec §2).
+## Perception sits under FTH, not a standalone WIS — §8's FTH/MAG replace WIS/INT,
+## so a Bonesetter is also the party's best lookout. LCK owns no skill (§7).
+
+const BY_ATTRIBUTE := {
+	"athletics": "str",
+	"intimidation": "str",
+	"stealth": "dex",
+	"sleight_of_hand": "dex",
+	"acrobatics": "dex",
+	"endurance": "con",
+	"perception": "fth",
+	"faith_lore": "fth",
+	"sorcery": "mag",
+}
+
+const IDS := ["athletics", "intimidation", "stealth", "sleight_of_hand", "acrobatics",
+	"endurance", "perception", "faith_lore", "sorcery"]
+
+
+static func exists(skill: String) -> bool:
+	return BY_ATTRIBUTE.has(skill)
+
+
+static func attribute(skill: String) -> String:
+	return str(BY_ATTRIBUTE.get(skill, ""))