fix(inventory-go): add Prodigal Spirit Drinker effect; document dmgMod key substitution; test wand mastery fallback

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

go-services/inventory-go/od.go

@@ -416,6 +416,7 @@ var elemVsMonSpellEffects = map[int]odSpellEffect{
 	3250: {.03, .03}, // Major Spirit Thirst
 	4670: {.05, .05}, // Epic Spirit Thirst
 	6098: {.07, .07}, // Legendary Spirit Thirst
+	3735: {.15, 0},   // Prodigal Spirit Drinker
 }
 
 // buffedMaxDamage mirrors GetBuffedIntValueKey(218103842): base value minus
@@ -497,11 +498,12 @@ func computeOD(raw map[string]any) (float64, bool) {
 	}
 	bv, ok := bestValues[key]
 	if !ok && oc == 31 {
-		// Wands: our probe showed some wands lack key 353 (mastery), which
+		// Mastery-0 retry for wands: an ADDITION over UB (UB's
-		// defaults to 0 via ivI — but retry explicitly with mastery 0 so the
+		// DataTable.Select has no retry; our captured wands may carry a
-		// void VR wand row (43,12,...) stays reachable while items that
+		// mastery key 353 while the table's wand rows use mastery 0).
-		// genuinely carry a different mastery value still fall back to the
+		// Keeps the void VR wand row (43,12,...) reachable on the first
-		// normal (34|43, 0, ...) rows.
+		// exact-match attempt while other mastery-carrying wands fall back
+		// to the normal (34|43, 0, ...) rows.
 		key.mastery = 0
 		bv, ok = bestValues[key]
 	}
@@ -550,6 +552,11 @@ func computeOD(raw map[string]any) (float64, bool) {
 			remaining = 0
 		}
 
+		// NOTE: UB's literal CalcMissileDamage reads DoubleValues[63], but no
+		// DoubleValueKey ordinal 63 exists (verified against Decal.Adapter) —
+		// that line is a stale/bugged reference in the UB source. The correct
+		// populated key is 167772174 (DamageBonus), consistent with UB's own
+		// CalcedBuffedMissileDamage. Do NOT "fix" this back to 63.
 		dmgMod := dvF(dv, "167772174", 0)*100 - 100
 		bDmg := float64(buffedMaxDamage(raw, iv))
 		if bDmg <= 10 {

go-services/inventory-go/od_test.go

@@ -23,6 +23,38 @@ func TestOD_Wand(t *testing.T) {
 	}
 }
 
+// Wand with an ACTIVE Prodigal Spirit Drinker (3735, change .15, bonus 0):
+// shown ElemVsMonsters 1.55 un-buffs to 1.55 − .15 = 1.40 → OD +22, same
+// underlying weapon as TestOD_Wand.
+func TestOD_WandActiveProdigalSpiritDrinker(t *testing.T) {
+	raw := map[string]any{
+		"ObjectClass":  31.0,
+		"IntValues":    map[string]any{"159": 34.0, "160": 385.0},
+		"DoubleValues": map[string]any{"152": 1.55, "167772169": 8.0},
+		"Spells":       []any{}, "ActiveSpells": []any{3735.0},
+	}
+	od, ok := computeOD(raw)
+	if !ok || !approx(od, 22.0) {
+		t.Fatalf("wand w/ active Prodigal SD OD = %v ok=%v, want +22", od, ok)
+	}
+}
+
+// Wand carrying a mastery value (353) with no matching wand table row: the
+// exact-match lookup on (34,5,0,385) misses, and the mastery-0 retry must hit
+// the (34,0,0,385) row → OD +22 as in TestOD_Wand.
+func TestOD_WandMasteryFallback(t *testing.T) {
+	raw := map[string]any{
+		"ObjectClass":  31.0,
+		"IntValues":    map[string]any{"159": 34.0, "353": 5.0, "160": 385.0},
+		"DoubleValues": map[string]any{"152": 1.40, "167772169": 8.0},
+		"Spells":       []any{}, "ActiveSpells": []any{},
+	}
+	od, ok := computeOD(raw)
+	if !ok || !approx(od, 22.0) {
+		t.Fatalf("wand mastery-fallback OD = %v ok=%v, want +22", od, ok)
+	}
+}
+
 // Non-loot (no workmanship) → no OD.
 func TestOD_NonLootNull(t *testing.T) {
 	raw := map[string]any{