diff --git a/packages/chess/src/engine.ts b/packages/chess/src/engine.ts
index cb0e49c..17678fe 100644
--- a/packages/chess/src/engine.ts
+++ b/packages/chess/src/engine.ts
@@ -80,6 +80,24 @@ import {
 import type { ModifierProfile } from "./modifiers/types.js";
 import { CustomModifierRegistry } from "./modifiers/custom/registry.js";
 import type { CustomModifierDescriptor } from "./modifiers/custom/types.js";
+import {
+  assertSeedConsumerIntegrity,
+  getEngineSeedManifest,
+} from "./modifiers/primitives/manifest.js";
+
+// Q3.2: run the primitive-seed consumer integrity check once, lazily
+// on first engine construction. Module load order (primitive
+// side-effect registrations, consumer registerAttrConsumer calls)
+// may still be resolving at top-level import time; deferring to the
+// first engine ensures every module in the graph has had a chance
+// to self-register. The check throws loudly if any primitive's
+// declared seedsAttrs has no corresponding registered consumer.
+let integrityChecked = false;
+function runIntegrityCheckOnce(): void {
+  if (integrityChecked) return;
+  integrityChecked = true;
+  assertSeedConsumerIntegrity();
+}
 
 type MoveGetter = (session: Session, pieceId: EntityId) => LegalMove[];
 
@@ -463,6 +481,7 @@ export class ChessEngine {
   constructor(activePresets?: ActivePresetSet);
   constructor(opts: EngineOptions);
   constructor(arg?: ActivePresetSet | EngineOptions) {
+    runIntegrityCheckOnce();
     this.session = new Session({ autoFire: false });
 
     // Normalize the argument: ActivePresetSet stays as-is (legacy
@@ -812,13 +831,20 @@ export class ChessEngine {
     }
 
     // Default: any damage is lethal. Retract every effective piece
-    // attribute (core + preset-declared) so downstream queries see the
-    // piece as truly gone.
+    // attribute (core + preset-declared + primitive-seeded) so
+    // downstream queries see the piece as truly gone. The
+    // primitive-seed manifest (Q4.6) covers T3-authored attrs that
+    // aren't declared by any preset's `pieceAttributes` list.
     for (const attr of this.effectivePieceAttrs) {
       if (this.session.contains(target, attr)) {
         this.session.retract(target, attr);
       }
     }
+    for (const attr of getEngineSeedManifest(this.customModifiers)) {
+      if (this.session.contains(target, attr)) {
+        this.session.retract(target, attr);
+      }
+    }
     return { died: true };
   }
 
diff --git a/packages/chess/src/modifiers/apply.ts b/packages/chess/src/modifiers/apply.ts
index 9204095..72128fb 100644
--- a/packages/chess/src/modifiers/apply.ts
+++ b/packages/chess/src/modifiers/apply.ts
@@ -77,6 +77,25 @@ import {
   fireOnTurnStartHooks,
   snapshotHp,
 } from "./triggers.js";
+import { registerAttrConsumer } from "./primitives/manifest.js";
+
+// Q3.2 consumer declarations: this module reads every attr listed
+// below in the integration preset's onDamage / filterMoves / after-
+// move trigger dispatchers. Declaring them here anchors the load-
+// time integrity check — if a primitive later starts writing an
+// attr not in this list, the engine boot surfaces it loudly.
+registerAttrConsumer("AbsorbDamageAttr");
+registerAttrConsumer("AbsorbDamageRate");
+registerAttrConsumer("ReflectDamagePercent");
+registerAttrConsumer("BlockedMoveTypes");
+registerAttrConsumer("DamageResistance");
+registerAttrConsumer("CaptureFlags");
+registerAttrConsumer("DirectionAdditions");
+registerAttrConsumer("OnTurnStartHooks");
+registerAttrConsumer("OnCaptureHooks");
+registerAttrConsumer("OnDamagedHooks");
+registerAttrConsumer("ConditionalHooks");
+registerAttrConsumer("AuraSpec");
 
 /**
  * Per-engine pre-move HP snapshot, used by the on-damaged trigger
diff --git a/packages/chess/src/modifiers/auras.test.ts b/packages/chess/src/modifiers/auras.test.ts
index 151228f..61b959b 100644
--- a/packages/chess/src/modifiers/auras.test.ts
+++ b/packages/chess/src/modifiers/auras.test.ts
@@ -171,6 +171,48 @@ describe("computeAuraFacts", () => {
     }
   });
 
+  it("mutual auras converge in a single pass (Q4.7)", () => {
+    // Two pieces each emit an aura targeting the other. The walker
+    // iterates sources independently, so each aura's contribution is
+    // computed against the SNAPSHOT of positions at compute time —
+    // meaning A sees B's aura and B sees A's aura in a single pass.
+    // This is the intended semantics: auras are declarative (based on
+    // radius + delta + geometry), not iterative (no fixpoint loop).
+    const engine = new ChessEngine();
+
+    // White king (e1, sq 4) and black king (e8, sq 60) are 7 squares
+    // apart — Chebyshev 7. Use radius 7 so both can reach each other.
+    const whiteKing = findPieceAtSquare(engine, 4);
+    const blackKing = findPieceAtSquare(engine, 60);
+    seedAura(engine, whiteKing, {
+      radius: 7,
+      targetAttr: "HpBonus",
+      delta: 1,
+    });
+    seedAura(engine, blackKing, {
+      radius: 7,
+      targetAttr: "HpBonus",
+      delta: 2,
+    });
+
+    computeAuraFacts(engine.session);
+
+    // White king receives black king's aura (+2). Black king receives
+    // white king's aura (+1). Self-application is skipped (unit-tested
+    // elsewhere) so the auras don't compound on their own sources.
+    expect(getContribs(engine, whiteKing)?.["HpBonus"]).toBe(2);
+    expect(getContribs(engine, blackKing)?.["HpBonus"]).toBe(1);
+
+    // A second compute pass produces identical results — mutual auras
+    // don't cascade or multiply across recomputes. The engine's
+    // onAfterMove cadence is once-per-move; if users ever want
+    // "aura of aura" semantics they can layer add-to-attribute on
+    // top of seed-attribute deliberately.
+    computeAuraFacts(engine.session);
+    expect(getContribs(engine, whiteKing)?.["HpBonus"]).toBe(2);
+    expect(getContribs(engine, blackKing)?.["HpBonus"]).toBe(1);
+  });
+
   it("engine's onAfterMove hook recomputes auras automatically when a profile is active", async () => {
     // Use a no-op modifier profile so the __modifier-profile-integration__
     // preset auto-activates — that's the only way onAfterMove fires
diff --git a/packages/chess/src/modifiers/effective-attr.ts b/packages/chess/src/modifiers/effective-attr.ts
index 7d9ebc0..ca881fd 100644
--- a/packages/chess/src/modifiers/effective-attr.ts
+++ b/packages/chess/src/modifiers/effective-attr.ts
@@ -19,6 +19,14 @@
  */
 import type { EntityId, Session } from "@paratype/rete";
 import type { ChessAttrKey, ChessAttrMap } from "../schema.js";
+import { registerAttrConsumer } from "./primitives/manifest.js";
+
+// Q3.2: this helper is the primary consumer of numeric attrs that
+// layer aura contributions. It reads HpBonus and RangeBonus (via
+// callers), and AuraContributions itself.
+registerAttrConsumer("HpBonus");
+registerAttrConsumer("RangeBonus");
+registerAttrConsumer("AuraContributions");
 
 /**
  * Read a numeric attribute and layer the aura contribution (if any).
diff --git a/packages/chess/src/modifiers/primitives/absorb-damage-with-attribute.ts b/packages/chess/src/modifiers/primitives/absorb-damage-with-attribute.ts
index add977b..0c6e4dc 100644
--- a/packages/chess/src/modifiers/primitives/absorb-damage-with-attribute.ts
+++ b/packages/chess/src/modifiers/primitives/absorb-damage-with-attribute.ts
@@ -1,4 +1,5 @@
 import { z } from "zod";
+import type { ChessAttrKey } from "../../schema.js";
 import { PRIMITIVE_REGISTRY } from "./registry.js";
 import type { EffectPrimitive, PrimitiveApplyContext } from "./types.js";
 
@@ -15,6 +16,20 @@ const descriptor: EffectPrimitive<Params> = {
   description:
     "Seed absorb-damage facts so damage can consume an attribute before HP.",
   paramsSchema: schema,
+  // Static portion: the two absorb control facts. The dynamic
+  // `params.attr` (e.g. "ShieldCharges") is also touched but the
+  // USER seeds it separately via seed-attribute; this primitive
+  // doesn't own that attr's lifecycle.
+  seedsAttrs: ["AbsorbDamageAttr", "AbsorbDamageRate"],
+  seedsAttrsFor(params: unknown): readonly ChessAttrKey[] {
+    const p = params as Partial<Params> | undefined;
+    const dynamic = p?.attr !== undefined ? [p.attr as ChessAttrKey] : [];
+    return [
+      "AbsorbDamageAttr" as ChessAttrKey,
+      "AbsorbDamageRate" as ChessAttrKey,
+      ...dynamic,
+    ];
+  },
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     ctx.session.insert(ctx.pieceId, "AbsorbDamageAttr", params.attr);
     ctx.session.insert(ctx.pieceId, "AbsorbDamageRate", params.rate);
diff --git a/packages/chess/src/modifiers/primitives/add-aura.ts b/packages/chess/src/modifiers/primitives/add-aura.ts
index 5962c8e..c8d3385 100644
--- a/packages/chess/src/modifiers/primitives/add-aura.ts
+++ b/packages/chess/src/modifiers/primitives/add-aura.ts
@@ -16,6 +16,10 @@ const descriptor: EffectPrimitive<Params> = {
   description:
     "Seeds an AuraSpec fact entry consumed by the aura engine's recomputation phase.",
   paramsSchema: schema,
+  // Source writes AuraSpec. Target pieces receive AuraContributions
+  // derived by computeAuraFacts — that's a separate pass, not a
+  // direct primitive write, so we don't declare it here.
+  seedsAttrs: ["AuraSpec"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing =
       (ctx.session.get(ctx.pieceId, "AuraSpec") as
diff --git a/packages/chess/src/modifiers/primitives/add-direction.ts b/packages/chess/src/modifiers/primitives/add-direction.ts
index 7424b30..06a3c5a 100644
--- a/packages/chess/src/modifiers/primitives/add-direction.ts
+++ b/packages/chess/src/modifiers/primitives/add-direction.ts
@@ -43,6 +43,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Add Direction",
   description: "Appends movement directions into DirectionAdditions with dedupe.",
   paramsSchema: schema,
+  seedsAttrs: ["DirectionAdditions"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing = ctx.session.get(ctx.pieceId, "DirectionAdditions");
     const existingDirections = existing ?? [];
diff --git a/packages/chess/src/modifiers/primitives/add-to-attribute.ts b/packages/chess/src/modifiers/primitives/add-to-attribute.ts
index 9edbf90..7c7ec59 100644
--- a/packages/chess/src/modifiers/primitives/add-to-attribute.ts
+++ b/packages/chess/src/modifiers/primitives/add-to-attribute.ts
@@ -1,4 +1,5 @@
 import { z } from "zod";
+import type { ChessAttrKey } from "../../schema.js";
 import { PRIMITIVE_REGISTRY } from "./registry.js";
 import type { EffectPrimitive, PrimitiveApplyContext } from "./types.js";
 
@@ -13,6 +14,10 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Add To Attribute",
   description: "Adds delta to the current attribute value, treating missing as 0.",
   paramsSchema: schema,
+  seedsAttrsFor(params: unknown): readonly ChessAttrKey[] {
+    const p = params as Partial<Params> | undefined;
+    return p?.attr !== undefined ? [p.attr as ChessAttrKey] : [];
+  },
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing = ctx.session.get(ctx.pieceId, params.attr);
     const baseValue = existing === undefined ? 0 : existing;
diff --git a/packages/chess/src/modifiers/primitives/block-move-type.ts b/packages/chess/src/modifiers/primitives/block-move-type.ts
index 22c3429..ff68ee0 100644
--- a/packages/chess/src/modifiers/primitives/block-move-type.ts
+++ b/packages/chess/src/modifiers/primitives/block-move-type.ts
@@ -15,6 +15,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Block Move Type",
   description: "Seed blocked move types for deferred move-filter integration.",
   paramsSchema: schema,
+  seedsAttrs: ["BlockedMoveTypes"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existingRaw = ctx.session.contains(ctx.pieceId, "BlockedMoveTypes")
       ? ctx.session.get(ctx.pieceId, "BlockedMoveTypes")
diff --git a/packages/chess/src/modifiers/primitives/conditional.ts b/packages/chess/src/modifiers/primitives/conditional.ts
index ab55717..8b50ebb 100644
--- a/packages/chess/src/modifiers/primitives/conditional.ts
+++ b/packages/chess/src/modifiers/primitives/conditional.ts
@@ -55,6 +55,7 @@ const descriptor: EffectPrimitive<Params> = {
   description:
     "Seeds ConditionalHooks entries consumed by the trigger evaluation pipeline.",
   paramsSchema: schema,
+  seedsAttrs: ["ConditionalHooks"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing =
       (ctx.session.get(ctx.pieceId, "ConditionalHooks") as
diff --git a/packages/chess/src/modifiers/primitives/manifest.test.ts b/packages/chess/src/modifiers/primitives/manifest.test.ts
new file mode 100644
index 0000000..5ab3d19
--- /dev/null
+++ b/packages/chess/src/modifiers/primitives/manifest.test.ts
@@ -0,0 +1,114 @@
+/**
+ * Manifest integrity tests (T3 audit Q3.2, Q4.6).
+ *
+ * These tests exercise the static manifest + consumer-registration
+ * API in isolation so the load-time integrity check stays honest as
+ * future primitives are added.
+ */
+import { describe, expect, it } from "vitest";
+import {
+  assertSeedConsumerIntegrity,
+  collectDynamicSeedsInTree,
+  getStaticPrimitiveSeedManifest,
+  getRegisteredConsumers,
+} from "./manifest.js";
+import "./index.js";
+// Load consumer modules so their registerAttrConsumer calls fire.
+// Normal engine construction pulls these in transitively; the
+// isolated test needs them explicit.
+import "../apply.js";
+import "../effective-attr.js";
+import "../../rules/promotion.js";
+
+describe("primitive seed manifest (Q4.6)", () => {
+  it("includes every statically-declared primitive attr", () => {
+    const manifest = getStaticPrimitiveSeedManifest();
+    // At minimum these ten are known from the 15 T3 primitives that
+    // declare static seedsAttrs. The dynamic-attr primitives
+    // (seed-attribute, add-to-attribute, multiply-attribute) don't
+    // appear in the static list and are handled via
+    // seedsAttrsFor at cleanup time.
+    const expected = [
+      "ReflectDamagePercent",
+      "BlockedMoveTypes",
+      "RangeBonus",
+      "PromotionOverride",
+      "DirectionAdditions",
+      "CaptureFlags",
+      "AuraSpec",
+      "OnTurnStartHooks",
+      "OnCaptureHooks",
+      "OnDamagedHooks",
+      "ConditionalHooks",
+      "AbsorbDamageAttr",
+      "AbsorbDamageRate",
+    ];
+    for (const attr of expected) {
+      expect(manifest).toContain(attr);
+    }
+  });
+
+  it("collectDynamicSeedsInTree walks nested primitives and collects per-descriptor attrs", () => {
+    // Descriptor with a seed-attribute inside an on-capture trigger —
+    // the cleanup path needs to discover BOTH "OnCaptureHooks" (from
+    // on-capture's static seedsAttrs) AND "HpBonus" (from the nested
+    // seed-attribute's dynamic seedsAttrsFor).
+    const tree = [
+      {
+        kind: "on-capture" as const,
+        params: {
+          primitives: [
+            {
+              kind: "seed-attribute" as const,
+              params: { attr: "HpBonus", value: 7 },
+            },
+          ],
+        },
+      },
+    ];
+    const attrs = collectDynamicSeedsInTree(tree);
+    expect(attrs).toContain("OnCaptureHooks");
+    expect(attrs).toContain("HpBonus");
+  });
+
+  it("collectDynamicSeedsInTree tolerates malformed params silently", () => {
+    const tree = [
+      {
+        kind: "seed-attribute" as const,
+        params: { /* missing attr */ value: 1 },
+      },
+    ];
+    // No throw — just no dynamic attrs collected for this node.
+    const attrs = collectDynamicSeedsInTree(tree);
+    expect(attrs).toEqual([]);
+  });
+});
+
+describe("load-time consumer integrity (Q3.2)", () => {
+  it("every statically-declared primitive seed has a registered consumer", () => {
+    // The engine construction path triggers this assertion; we call
+    // it directly here to surface the failure mode in isolation.
+    // If this test fails, find the missing attr in the error message
+    // and either add a registerAttrConsumer call in the consuming
+    // subsystem or remove the primitive's seedsAttrs declaration.
+    expect(() => assertSeedConsumerIntegrity()).not.toThrow();
+  });
+
+  it("getRegisteredConsumers includes the attrs we expect", () => {
+    const consumers = getRegisteredConsumers();
+    // Core attrs layered by effective-attr.ts:
+    expect(consumers).toContain("HpBonus");
+    expect(consumers).toContain("RangeBonus");
+    expect(consumers).toContain("AuraContributions");
+    // Damage pipeline in apply.ts:
+    expect(consumers).toContain("ReflectDamagePercent");
+    expect(consumers).toContain("AbsorbDamageAttr");
+    // Movegen filter:
+    expect(consumers).toContain("BlockedMoveTypes");
+    // Trigger dispatchers:
+    expect(consumers).toContain("OnCaptureHooks");
+    expect(consumers).toContain("ConditionalHooks");
+    // Promotion:
+    expect(consumers).toContain("PromotionOverride");
+  });
+});
diff --git a/packages/chess/src/modifiers/primitives/manifest.ts b/packages/chess/src/modifiers/primitives/manifest.ts
new file mode 100644
index 0000000..11ec4c6
--- /dev/null
+++ b/packages/chess/src/modifiers/primitives/manifest.ts
@@ -0,0 +1,159 @@
+/**
+ * Primitive-seeded-attribute manifest (T3 audit Q3.2 + Q4.6).
+ *
+ * Walks PRIMITIVE_REGISTRY and collects the union of every
+ * ChessAttrKey any registered primitive could seed. Two consumers:
+ *
+ *  - Q4.6 (zombie cleanup): the engine's death-retract path retracts
+ *    every attr in the manifest from the dying piece so primitive-
+ *    seeded facts don't leak onto captured entities.
+ *
+ *  - Q3.2 (load-time consumer integrity): on engine boot we assert
+ *    every manifest entry has a registered consumer (reader) in at
+ *    least one of the known engine subsystems. Missing consumers
+ *    turn silent-inert primitives into a loud load-time failure.
+ *
+ * Dynamic-attr primitives (seed-attribute, add-to-attribute,
+ * multiply-attribute) use `seedsAttrsFor(params)` which needs per-
+ * entry params. The manifest used by cleanup collects the STATIC
+ * `seedsAttrs` plus any attrs observed from `seedsAttrsFor` on all
+ * currently-registered custom descriptors in the engine — callers
+ * that know the descriptor context pass it in; cleanup falls back
+ * to the static list on its own.
+ */
+import type { ChessAttrKey } from "../../schema.js";
+import { PRIMITIVE_REGISTRY } from "./registry.js";
+import type { CustomModifierRegistry } from "../custom/registry.js";
+import type { EffectPrimitiveNode } from "./types.js";
+
+/**
+ * The static half of the manifest — attrs every primitive declares
+ * it writes regardless of params. Cached once on first call; safe
+ * because PRIMITIVE_REGISTRY is append-only after module load (all
+ * registrations happen via side-effect imports at load time).
+ */
+let staticManifestCache: readonly ChessAttrKey[] | null = null;
+
+export function getStaticPrimitiveSeedManifest(): readonly ChessAttrKey[] {
+  if (staticManifestCache !== null) return staticManifestCache;
+  const seen = new Set<ChessAttrKey>();
+  for (const primitive of PRIMITIVE_REGISTRY.list()) {
+    const attrs = primitive.seedsAttrs;
+    if (attrs === undefined) continue;
+    for (const a of attrs) seen.add(a);
+  }
+  staticManifestCache = [...seen];
+  return staticManifestCache;
+}
+
+/**
+ * Walk a primitive-node tree and collect every attr it could seed
+ * via `seedsAttrsFor` (dynamic) AND `seedsAttrs` (static). Used by
+ * the zombie-cleanup path when a custom descriptor is in scope;
+ * combines with the static manifest above so the caller retracts
+ * both the broad always-written set AND the per-descriptor
+ * dynamic targets.
+ */
+export function collectDynamicSeedsInTree(
+  nodes: readonly EffectPrimitiveNode[],
+): readonly ChessAttrKey[] {
+  const seen = new Set<ChessAttrKey>();
+  const walk = (ns: readonly EffectPrimitiveNode[]): void => {
+    for (const node of ns) {
+      const primitive = PRIMITIVE_REGISTRY.get(node.kind);
+      if (primitive === undefined) continue;
+      if (primitive.seedsAttrs !== undefined) {
+        for (const a of primitive.seedsAttrs) seen.add(a);
+      }
+      if (primitive.seedsAttrsFor !== undefined) {
+        try {
+          for (const a of primitive.seedsAttrsFor(node.params)) seen.add(a);
+        } catch {
+          // Malformed params — skip this node's dynamic seeds.
+        }
+      }
+      if (primitive.childPrimitives !== undefined) {
+        try {
+          walk(primitive.childPrimitives(node.params));
+        } catch {
+          /* ignore */
+        }
+      }
+    }
+  };
+  walk(nodes);
+  return [...seen];
+}
+
+/**
+ * Full per-engine seed manifest: static attrs + every attr any
+ * currently-registered custom descriptor in the engine could seed
+ * (walking their primitive trees). The death-retract path uses this
+ * so both 'always-written' and 'user-authored dynamic target' attrs
+ * get cleaned up when a piece dies.
+ */
+export function getEngineSeedManifest(
+  customRegistry: CustomModifierRegistry | undefined,
+): readonly ChessAttrKey[] {
+  const seen = new Set<ChessAttrKey>(getStaticPrimitiveSeedManifest());
+  if (customRegistry === undefined) return [...seen];
+  for (const descriptor of customRegistry.list()) {
+    for (const a of collectDynamicSeedsInTree(descriptor.primitives)) {
+      seen.add(a);
+    }
+  }
+  return [...seen];
+}
+
+// ─── Q3.2: load-time consumer integrity ─────────────────────────────
+
+/**
+ * Registered consumer set — engine subsystems declare here that they
+ * read an attr, so the integrity check can verify every primitive-
+ * seeded attr has at least one reader.
+ */
+const REGISTERED_CONSUMERS = new Set<ChessAttrKey>();
+
+/**
+ * Called by engine subsystems (movegen filters, damage pipeline,
+ * effective-attr readers, aura recompute, etc.) at module-load time
+ * to declare 'I read this attr'. Idempotent.
+ */
+export function registerAttrConsumer(attr: ChessAttrKey): void {
+  REGISTERED_CONSUMERS.add(attr);
+}
+
+/** Snapshot for tests and the integrity check. */
+export function getRegisteredConsumers(): readonly ChessAttrKey[] {
+  return [...REGISTERED_CONSUMERS];
+}
+
+/**
+ * Assert that every statically-declared primitive-seeded attr has at
+ * least one engine consumer. Call once after the full module graph
+ * has loaded (e.g. the first time an engine is constructed).
+ *
+ * Throws a single aggregated error listing missing consumers so users
+ * see all gaps at once rather than rebuilding per-missing.
+ */
+export function assertSeedConsumerIntegrity(): void {
+  const unsatisfied: ChessAttrKey[] = [];
+  for (const attr of getStaticPrimitiveSeedManifest()) {
+    if (!REGISTERED_CONSUMERS.has(attr)) unsatisfied.push(attr);
+  }
+  if (unsatisfied.length > 0) {
+    throw new Error(
+      `primitive-seed consumer integrity check failed: ` +
+        `${unsatisfied.length} attr(s) have no registered consumer ` +
+        `[${unsatisfied.join(", ")}]. Register via registerAttrConsumer() ` +
+        `from the subsystem that reads the attr, or remove the primitive.`,
+    );
+  }
+}
+
+// Exported for tests only. Clears the static manifest cache so a
+// test can re-register primitives and re-run the integrity check.
+export function __resetManifestCacheForTesting(): void {
+  staticManifestCache = null;
+  REGISTERED_CONSUMERS.clear();
+}
diff --git a/packages/chess/src/modifiers/primitives/modify-movement-range.ts b/packages/chess/src/modifiers/primitives/modify-movement-range.ts
index c868cff..8f7745c 100644
--- a/packages/chess/src/modifiers/primitives/modify-movement-range.ts
+++ b/packages/chess/src/modifiers/primitives/modify-movement-range.ts
@@ -13,6 +13,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Modify Movement Range",
   description: "Additively contributes to the existing RangeBonus attribute.",
   paramsSchema: schema,
+  seedsAttrs: ["RangeBonus"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing = ctx.session.contains(ctx.pieceId, "RangeBonus")
       ? ctx.session.get(ctx.pieceId, "RangeBonus")
diff --git a/packages/chess/src/modifiers/primitives/multiply-attribute.ts b/packages/chess/src/modifiers/primitives/multiply-attribute.ts
index 53fbb6f..16511b5 100644
--- a/packages/chess/src/modifiers/primitives/multiply-attribute.ts
+++ b/packages/chess/src/modifiers/primitives/multiply-attribute.ts
@@ -1,4 +1,5 @@
 import { z } from "zod";
+import type { ChessAttrKey } from "../../schema.js";
 import { PRIMITIVE_REGISTRY } from "./registry.js";
 import type { EffectPrimitive, PrimitiveApplyContext } from "./types.js";
 
@@ -13,6 +14,10 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Multiply Attribute",
   description: "Multiplies an existing attribute value by the provided factor.",
   paramsSchema: schema,
+  seedsAttrsFor(params: unknown): readonly ChessAttrKey[] {
+    const p = params as Partial<Params> | undefined;
+    return p?.attr !== undefined ? [p.attr as ChessAttrKey] : [];
+  },
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing = ctx.session.get(ctx.pieceId, params.attr);
     if (existing === undefined) {
diff --git a/packages/chess/src/modifiers/primitives/on-capture.ts b/packages/chess/src/modifiers/primitives/on-capture.ts
index 7581e6f..212b9e8 100644
--- a/packages/chess/src/modifiers/primitives/on-capture.ts
+++ b/packages/chess/src/modifiers/primitives/on-capture.ts
@@ -27,6 +27,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "On Capture",
   description: "Seeds OnCaptureHooks entries consumed during capture events.",
   paramsSchema: schema,
+  seedsAttrs: ["OnCaptureHooks"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing =
       (ctx.session.get(ctx.pieceId, "OnCaptureHooks") as
diff --git a/packages/chess/src/modifiers/primitives/on-damaged.ts b/packages/chess/src/modifiers/primitives/on-damaged.ts
index b70ec41..9f11774 100644
--- a/packages/chess/src/modifiers/primitives/on-damaged.ts
+++ b/packages/chess/src/modifiers/primitives/on-damaged.ts
@@ -27,6 +27,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "On Damaged",
   description: "Seeds OnDamagedHooks entries consumed during damage events.",
   paramsSchema: schema,
+  seedsAttrs: ["OnDamagedHooks"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing =
       (ctx.session.get(ctx.pieceId, "OnDamagedHooks") as
diff --git a/packages/chess/src/modifiers/primitives/on-turn-start.ts b/packages/chess/src/modifiers/primitives/on-turn-start.ts
index a16db5e..f2826cb 100644
--- a/packages/chess/src/modifiers/primitives/on-turn-start.ts
+++ b/packages/chess/src/modifiers/primitives/on-turn-start.ts
@@ -28,6 +28,7 @@ const descriptor: EffectPrimitive<Params> = {
   description:
     "Seeds OnTurnStartHooks entries consumed during the engine's turn-start phase.",
   paramsSchema: schema,
+  seedsAttrs: ["OnTurnStartHooks"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing =
       (ctx.session.get(ctx.pieceId, "OnTurnStartHooks") as
diff --git a/packages/chess/src/modifiers/primitives/override-promotion.ts b/packages/chess/src/modifiers/primitives/override-promotion.ts
index 856eedf..7f02f9c 100644
--- a/packages/chess/src/modifiers/primitives/override-promotion.ts
+++ b/packages/chess/src/modifiers/primitives/override-promotion.ts
@@ -14,6 +14,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Override Promotion",
   description: "Write PromotionOverride directly to enforce a promotion target.",
   paramsSchema: schema,
+  seedsAttrs: ["PromotionOverride"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const target: PieceType = params.target;
     ctx.session.insert(ctx.pieceId, "PromotionOverride", target);
diff --git a/packages/chess/src/modifiers/primitives/reflect-damage.ts b/packages/chess/src/modifiers/primitives/reflect-damage.ts
index a7baa32..eb685ef 100644
--- a/packages/chess/src/modifiers/primitives/reflect-damage.ts
+++ b/packages/chess/src/modifiers/primitives/reflect-damage.ts
@@ -13,6 +13,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Reflect Damage",
   description: "Seed reflected-damage percentage for deferred damage-pipeline wiring.",
   paramsSchema: schema,
+  seedsAttrs: ["ReflectDamagePercent"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     ctx.session.insert(ctx.pieceId, "ReflectDamagePercent", params.percentage);
   },
diff --git a/packages/chess/src/modifiers/primitives/seed-attribute.ts b/packages/chess/src/modifiers/primitives/seed-attribute.ts
index f60ac95..9aa6ee4 100644
--- a/packages/chess/src/modifiers/primitives/seed-attribute.ts
+++ b/packages/chess/src/modifiers/primitives/seed-attribute.ts
@@ -39,6 +39,13 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Seed Attribute",
   description: "Seeds a fact on the target piece, overwriting existing value.",
   paramsSchema: schema,
+  // Dynamic seed: writes whatever attr the user chose in params.
+  // Consumer registry trust-mapping falls back to "any attr the user
+  // targets" — load-time manifest can't narrow this further.
+  seedsAttrsFor(params: unknown): readonly ChessAttrKey[] {
+    const p = params as Partial<Params> | undefined;
+    return p?.attr !== undefined ? [p.attr as ChessAttrKey] : [];
+  },
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     if (!isChessAttrKey(params.attr)) {
       return;
diff --git a/packages/chess/src/modifiers/primitives/set-capture-flag.ts b/packages/chess/src/modifiers/primitives/set-capture-flag.ts
index 53e9704..10d5886 100644
--- a/packages/chess/src/modifiers/primitives/set-capture-flag.ts
+++ b/packages/chess/src/modifiers/primitives/set-capture-flag.ts
@@ -22,6 +22,7 @@ const descriptor: EffectPrimitive<Params> = {
   label: "Set Capture Flag",
   description: "Bitwise-ORs one capture flag into CaptureFlags.",
   paramsSchema: schema,
+  seedsAttrs: ["CaptureFlags"],
   apply(ctx: PrimitiveApplyContext, params: Params): void {
     const existing = ctx.session.get(ctx.pieceId, "CaptureFlags");
     const baseFlags = existing === undefined ? 0 : existing;
diff --git a/packages/chess/src/modifiers/primitives/types.ts b/packages/chess/src/modifiers/primitives/types.ts
index d81725c..4c016de 100644
--- a/packages/chess/src/modifiers/primitives/types.ts
+++ b/packages/chess/src/modifiers/primitives/types.ts
@@ -1,6 +1,7 @@
 import type { EntityId, Session } from "@paratype/rete";
 import type { ZodType } from "zod";
 import type { ChessEngine } from "../../engine.js";
+import type { ChessAttrKey } from "../../schema.js";
 
 /**
  * T3 primitive ids (ADR-2).
@@ -57,6 +58,25 @@ export interface PrimitiveApplyContext {
  *
  * `childPrimitives` is provided by primitives that own nested primitive lists
  * (e.g. trigger/conditional primitives) so validators can walk the tree.
+ *
+ * Seed declarations (`seedsAttrs` / `seedsAttrsFor`) are consumed by:
+ *  - Load-time manifest check (Q3.2): engine boot walks
+ *    PRIMITIVE_REGISTRY and asserts every declared attr has a
+ *    consumer subsystem registered (effective-attr helper, movegen
+ *    filters, damage pipeline, etc.). Missing consumers turn silent
+ *    runtime failure into a loud load-time assertion.
+ *  - Zombie-fact cleanup (Q4.6): when a piece dies, the engine
+ *    retracts every attr a primitive could have seeded, not just
+ *    the preset-declared core attrs.
+ *
+ * A primitive may declare EITHER or BOTH:
+ *  - `seedsAttrs`: static list of attrs always written.
+ *  - `seedsAttrsFor(params)`: dynamic list for params-dependent
+ *    targets (seed-attribute's `attr` param, etc.). Called with
+ *    per-instance params at cleanup/manifest time.
+ *
+ * Consumers merge both lists. Primitives that only orchestrate
+ * nested children may declare empty arrays / omit both.
  */
 export interface EffectPrimitive<Params = unknown> {
   readonly kind: PrimitiveKind;
@@ -66,6 +86,8 @@ export interface EffectPrimitive<Params = unknown> {
   readonly apply: (ctx: PrimitiveApplyContext, params: Params) => void;
   readonly maxDepth?: number;
   readonly childPrimitives?: (params: Params) => EffectPrimitiveNode[];
+  readonly seedsAttrs?: readonly ChessAttrKey[];
+  readonly seedsAttrsFor?: (params: unknown) => readonly ChessAttrKey[];
 }
 
 export type { Session };
diff --git a/packages/chess/src/presets/piece-hp.ts b/packages/chess/src/presets/piece-hp.ts
index e3a14b3..0421322 100644
--- a/packages/chess/src/presets/piece-hp.ts
+++ b/packages/chess/src/presets/piece-hp.ts
@@ -53,6 +53,7 @@
 import { PRESET_REGISTRY } from "./registry.js";
 import type { GameResult } from "../engine.js";
 import type { Session, EntityId } from "@paratype/rete";
+import { getEngineSeedManifest } from "../modifiers/primitives/manifest.js";
 
 /** Starting HP for every piece. Future work: make this per-type so
  *  pawns have 1 HP and queens have 3, etc. */
@@ -150,12 +151,17 @@ PRESET_REGISTRY.register({
     }
 
     // Lethal. Retract all effective piece attrs ourselves (core +
-    // whatever other presets declared) so nothing is left behind.
-    // Returning died:true tells upstream callers (capture path) that
-    // the attacker should advance.
+    // whatever other presets declared) AND every primitive-seeded
+    // attr (Q4.6 — HpBonus, ReflectDamagePercent, AuraSpec, trigger
+    // hooks, etc.) so nothing is left behind. Returning died:true
+    // tells upstream callers (capture path) that the attacker
+    // should advance.
     for (const attr of engine.effectivePieceAttrs) {
       if (session.contains(target, attr)) session.retract(target, attr);
     }
+    for (const attr of getEngineSeedManifest(engine.customModifiers)) {
+      if (session.contains(target, attr)) session.retract(target, attr);
+    }
     return { consume: true, died: true };
   },
 
diff --git a/packages/chess/src/rules/promotion.ts b/packages/chess/src/rules/promotion.ts
index 9c81ac1..2234c5c 100644
--- a/packages/chess/src/rules/promotion.ts
+++ b/packages/chess/src/rules/promotion.ts
@@ -18,6 +18,11 @@
  */
 import type { Session, EntityId } from "@paratype/rete";
 import type { PieceType, PieceColor, Square } from "../schema.js";
+import { registerAttrConsumer } from "../modifiers/primitives/manifest.js";
+
+// Q3.2: promotion.ts reads PromotionOverride to gate / override
+// promotion candidates.
+registerAttrConsumer("PromotionOverride");
 import { PROMOTION_PIECES } from "../schema.js";
 import { rankOf } from "../coord.js";
 import type { LegalMove } from "./types.js";