D&D: class-balance Phase 2 — passive + L5 subclass tuning + in-tier parity assertion

The Phase 1 per-class-mean summary was hiding the truth — most cells are
floor/ceiling-saturated (L10+ pinned at 1.0, L1-4 caster cells at high
tier pinned at 0.0), so means barely budge when you tune passives. Added
a per-(level, tier) cross-class spread diagnostic to the matrix log,
then tuned with the levers from doc §6 in priority order:

1. Class passives (dnd_passives.go) — caster trailers (Bard, Mage,
   Warlock, Sorcerer) gained level + casting-stat-scaled FlatDmgStart
   bursts so the L1-4 chassis isn't a quarterstaff + one weak spell
   against a T2-T3 monster; small DamageBonus riders (Mage/Bard/
   Sorcerer/Rogue +5%, Warlock 10→12%) and +1 attack for Bard/Warlock
   close the steady-DPS gap. Added clampNonNeg so ability-mod-scaled
   additions never go negative on sub-10-stat sheets.

2. Subclass L5 tiers (dnd_subclass_combat.go) — the three Sorcerer L5
   picks (Wild/Storm/Draconic) and Warlock Great Old One were defense-
   only or near-inert pre-tune; each gained a small bite (DamageBonus
   +0.10, or a FlatDmgStart burst for Storm) so the L5 chassis can press
   through a T4 monster.

Parity band locked in TestClassBalance_Phase1_FullMatrix: cross-class
spread ≤ 35pp on the in-tier diagonal — (level, tier) cells where the
level is appropriate for the tier (T1: L1-4, T2: L3-7, T3: L5-10, T4:
L7-15, T5: L10-20). Off-tier cells (L1 mage at T3 dungeon etc.) are
still logged but not asserted: those are level-vs-tier mismatches and
casters at L1-4 can't muscle through a T3 monster on a single L1-slot
spell the way martials muscle through with weapon dice. Worst in-tier
cell after tuning: ~26pp at L3/T2. The 35pp band gives ~9pp Monte-Carlo
headroom over the worst signal at 200 trials/cell.

TestApplyClassPassives expectations updated to match the new passives.
Phase 0 spike still green, full plugin suite (-short) clean.

internal/plugin/dnd_subclass_combat.go

@@ -482,11 +482,14 @@ func applySubclassPassives(stats *CombatStats, mods *CombatModifiers, c *DnDChar
 		// Dragon Wings: mobility and a tougher frame — an 8% reduction and a
 		// small damage bump. L15 Draconic Presence: a frightful aura — 2
 		// rounds of SporeCloud miss chance.
+		// Phase 2 class-balance: L5 was defense-only; gave it a small bite
+		// (10% damage) so the L5 chassis isn't pure attrition vs T4 monsters.
 		if c.Level >= 5 {
 			stats.AC++
 			if mods.ArcaneWardHP < c.Level {
 				mods.ArcaneWardHP = c.Level
 			}
+			mods.DamageBonus += 0.10
 		}
 		if c.Level >= 7 {
 			mods.DamageBonus += 0.10
@@ -504,8 +507,13 @@ func applySubclassPassives(stats *CombatStats, mods *CombatModifiers, c *DnDChar
 		// FirstAttackBonus. L10 Controlled Chaos: a surge you actually aimed
 		// — a FlatDmgStart burst. L15 Spell Bombardment: dice that keep
 		// exploding — +15% damage.
+		// Phase 2 class-balance: bare advantage-on-opener left this subclass
+		// the weakest L5 caster pick (0.065 at T4 pre-tune vs Champion 0.92).
+		// Added a 10% damage rider — Wild Magic surges as flavor, ~+1d6 of
+		// chaos damage per round in mechanics.
 		if c.Level >= 5 {
 			mods.AssassinateAdvantage = true
+			mods.DamageBonus += 0.10
 		}
 		if c.Level >= 7 {
 			mods.FirstAttackBonus += 3
@@ -523,9 +531,13 @@ func applySubclassPassives(stats *CombatStats, mods *CombatModifiers, c *DnDChar
 		// weather — a small 5% reduction and 1 round of SporeCloud. L15
 		// Storm's Fury: incoming blows are answered with lightning —
 		// ReflectNext on the first hit.
+		// Phase 2 class-balance: init/speed alone left this subclass at 0.035
+		// T4 pre-tune. Pull a small slice of the L7 thunderclap forward so
+		// the L5 chassis has actual damage output.
 		if c.Level >= 5 {
 			mods.InitiativeBias += 1
 			stats.Speed += 2
+			mods.FlatDmgStart += 4 + c.Level/2
 		}
 		if c.Level >= 7 {
 			mods.FlatDmgStart += 5 + c.Level/2
@@ -587,9 +599,13 @@ func applySubclassPassives(stats *CombatStats, mods *CombatModifiers, c *DnDChar
 		// Thrall: a dominated mind fights beside you — the pet channel. L15:
 		// deeper psychic dominion keeps the thrall in the fight and sharpens
 		// your own assault (+10% damage).
+		// Phase 2 class-balance: L5 was defense-only (0.130 T4 pre-tune).
+		// Added a small bite so the L5 chassis can press the advantage when
+		// the foe misses.
 		if c.Level >= 5 {
 			mods.DamageReduct *= 0.95
 			mods.SporeCloud++
+			mods.DamageBonus += 0.10
 		}
 		if c.Level >= 7 {
 			mods.DamageReduct *= 0.92