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/adventure_arena.go

@@ -319,7 +319,16 @@ func (p *AdventurePlugin) resolveArenaSurvival(ctx MessageContext, run *ArenaRun
 	// Render combat log as phased messages + final outcome
 	phaseMessages := RenderCombatLogArena(result, char.DisplayName, monster.Name)
 	phaseMessages = p.prependCraftNarrative(ctx.Sender, phaseMessages)
+	if open := dndCombatOpeningLine(); open != "" && len(phaseMessages) > 0 {
+		phaseMessages[0] = "_" + open + "_\n\n" + phaseMessages[0]
+	}
 	finalMessage := renderArenaCombatFinalMessage(result, monster, reward, battleXP, run.Round)
+	// Boss = T5 final round. Use BossDeath flavor for that fight's win.
+	isBoss := run.Tier == 5
+	finalMessage += dndItalicize(dndCombatClosingLine(true, isBoss))
+	if rollLine := dndRollSummaryLine(result); rollLine != "" {
+		finalMessage += "\n" + rollLine
+	}
 
 	// Suppress the "(at risk)" line on the tier-completing round — those earnings
 	// are about to be locked in by the tier-complete branch below, so labelling
@@ -413,6 +422,9 @@ func (p *AdventurePlugin) resolveArenaDeath(ctx MessageContext, run *ArenaRun, c
 	lostEarnings := run.Earnings + run.TierEarnings
 
 	phaseMessages := RenderCombatLogArena(result, char.DisplayName, monster.Name)
+	if open := dndCombatOpeningLine(); open != "" && len(phaseMessages) > 0 {
+		phaseMessages[0] = "_" + open + "_\n\n" + phaseMessages[0]
+	}
 
 	dt := transitionDeath(DeathTransitionParams{
 		Char:          char,
@@ -442,6 +454,10 @@ func (p *AdventurePlugin) resolveArenaDeath(ctx MessageContext, run *ArenaRun, c
 	upsertArenaStats(run.UserID, 0, true, run.Tier)
 
 	finalMsg := renderArenaCombatFinalMessage(result, monster, 0, arenaParticipationXP, run.Round)
+	finalMsg += dndItalicize(dndCombatClosingLine(false, false))
+	if rollLine := dndRollSummaryLine(result); rollLine != "" {
+		finalMsg += "\n" + rollLine
+	}
 	if dt.PetRecovered {
 		finalMsg += fmt.Sprintf("\n\nYour pet dragged you out of the arena. Death timer reduced. All session earnings forfeited.")
 	} else {