Adv 2.0 D&D layer: Phases 1-8 + Phase 9 SP1+SP2

Combines all uncommitted D&D work into one checkpoint:

Phases 1-8 (per gogobee_dnd_session_summary.md):
- Race/class/stats system, !setup flow, !sheet, !respec
- d20-vs-AC combat with race/class passives, auto-migration
- XP/level-up, skill checks, NPC refund hooks
- Equipment slot mapping, rarity, !rest short/long
- Pre-arm active abilities, resource pools
- Bestiary, !roll/!stats/!level, onboarding DM
- Audit fixes A-I, flavor wiring under internal/flavor/
- Phase 8 weapon dice + armor AC tables (gogobee_equipment_appendix)

Phase 9 SP1 — spell system foundations:
- 79 SpellDefinitions (76 in-scope + 3 reaction-deferred)
- dnd_known_spells, dnd_spell_slots tables
- pending_cast / concentration_* columns on dnd_character
- Slot tables for Mage/Cleric/Ranger, DC + attack-bonus math
- Long-rest refreshes slots; respec wipes spell state
- Auto-grant default known list on !setup confirm and auto-migration

Phase 9 SP2 — !cast / !spells / !prepare commands:
- Out-of-combat HEAL and UTILITY resolve immediately
- Damage/control/buff queue as pending_cast for next combat
- Audit-style save-then-debit, slot refund on save failure
- !cast --drop, concentration supersession, prep-cap enforcement
- Reaction spells refused with Phase 11 note

SP3 (combat-time resolution of pending_cast) and SP4 (full prep/learn
tests) are next. Build clean, full test suite green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/plugin/dnd_equipment.go

@@ -0,0 +1,134 @@
+package plugin
+
+// Phase 4 — D&D equipment view.
+//
+// Strategy per v1.1 §7.3: legacy adventure_equipment is the source of truth
+// for what a player has equipped. The D&D layer maps the 5-slot legacy
+// scheme onto the 10-slot D&D scheme at read time. No migration writes
+// happen. The five new slots (legs, hands, ring_1, ring_2, amulet) are
+// reserved for future drops and stay empty for now.
+
+// DnDSlot is the canonical D&D equipment slot. legacy adventure_equipment
+// stores items under EquipmentSlot (weapon/armor/helmet/boots/tool); we
+// map those into D&D slots in mapLegacySlot.
+type DnDSlot string
+
+const (
+	DnDSlotHead     DnDSlot = "head"
+	DnDSlotChest    DnDSlot = "chest"
+	DnDSlotLegs     DnDSlot = "legs"
+	DnDSlotHands    DnDSlot = "hands"
+	DnDSlotFeet     DnDSlot = "feet"
+	DnDSlotMainHand DnDSlot = "main_hand"
+	DnDSlotOffHand  DnDSlot = "off_hand"
+	DnDSlotRing1    DnDSlot = "ring_1"
+	DnDSlotRing2    DnDSlot = "ring_2"
+	DnDSlotAmulet   DnDSlot = "amulet"
+)
+
+// dndSlotOrder controls display order for !sheet.
+var dndSlotOrder = []DnDSlot{
+	DnDSlotHead, DnDSlotChest, DnDSlotLegs, DnDSlotHands, DnDSlotFeet,
+	DnDSlotMainHand, DnDSlotOffHand,
+	DnDSlotRing1, DnDSlotRing2, DnDSlotAmulet,
+}
+
+// mapLegacySlot translates a legacy EquipmentSlot into the D&D slot it
+// occupies in the new view. The legacy `tool` slot is mapped to off_hand
+// since tools (pickaxes, fishing rods, etc.) function as off-hand items.
+func mapLegacySlot(s EquipmentSlot) DnDSlot {
+	switch s {
+	case SlotWeapon:
+		return DnDSlotMainHand
+	case SlotArmor:
+		return DnDSlotChest
+	case SlotHelmet:
+		return DnDSlotHead
+	case SlotBoots:
+		return DnDSlotFeet
+	case SlotTool:
+		return DnDSlotOffHand
+	}
+	return ""
+}
+
+// ── Rarity inference ─────────────────────────────────────────────────────────
+
+// DnDRarity tags an item for D&D-style display. Inferred from the legacy
+// tier + masterwork flag. New drops with explicit dnd_rarity (Phase 4+
+// loot generation) skip this inference.
+type DnDRarity string
+
+const (
+	RarityCommon    DnDRarity = "Common"
+	RarityUncommon  DnDRarity = "Uncommon"
+	RarityRare      DnDRarity = "Rare"
+	RarityEpic      DnDRarity = "Epic"
+	RarityLegendary DnDRarity = "Legendary"
+)
+
+// rarityIcon — leading symbol for !sheet rendering (color stand-ins for
+// terminals that don't render emoji color squares well).
+func rarityIcon(r DnDRarity) string {
+	switch r {
+	case RarityCommon:
+		return "⬜"
+	case RarityUncommon:
+		return "🟩"
+	case RarityRare:
+		return "🟦"
+	case RarityEpic:
+		return "🟪"
+	case RarityLegendary:
+		return "🟧"
+	}
+	return ""
+}
+
+// inferRarity maps legacy gear (tier + masterwork + arena_set) to a D&D
+// rarity tier. Used at read time when dnd_rarity is empty.
+func inferRarity(tier int, masterwork bool, arenaTier int) DnDRarity {
+	if masterwork {
+		// Masterwork is the legacy version of "this gear is special" —
+		// always treat as at least Rare to match its mechanical weight.
+		if tier >= 5 {
+			return RarityEpic
+		}
+		return RarityRare
+	}
+	if arenaTier > 0 {
+		// Arena set gear: rarity scales with arena tier.
+		switch arenaTier {
+		case 1, 2:
+			return RarityUncommon
+		case 3:
+			return RarityRare
+		case 4:
+			return RarityEpic
+		default:
+			return RarityLegendary
+		}
+	}
+	switch {
+	case tier <= 2:
+		return RarityCommon
+	case tier <= 4:
+		return RarityUncommon
+	case tier <= 6:
+		return RarityRare
+	case tier <= 8:
+		return RarityEpic
+	default:
+		return RarityLegendary
+	}
+}
+
+// equipmentRarity returns the rarity to display for an AdvEquipment row.
+// Honors any explicit dnd_rarity on the row (Phase 4+ loot drops);
+// otherwise falls back to inferRarity.
+func equipmentRarity(eq *AdvEquipment) DnDRarity {
+	if eq == nil {
+		return RarityCommon
+	}
+	return inferRarity(eq.Tier, eq.Masterwork, eq.ArenaTier)
+}