diff --git a/.github/justfile b/.github/justfile
index 2ea79ef..6fa72b9 100644
--- a/.github/justfile
+++ b/.github/justfile
@@ -45,6 +45,7 @@ core:
     @just gha::_step version-guard-local
     @just gha::_step version-guard-pr
     @just gha::_step fmt-check
+    @just gha::_step lint
     @just gha::_step build
     @just gha::_step test-rust
     @just gha::_step shim
diff --git a/justfile b/justfile
index b31db8e..51e7cfa 100644
--- a/justfile
+++ b/justfile
@@ -9,10 +9,10 @@ default:
 ci: (gha::core) (gha::browser)
 
 # Full pre-commit gates, including local consumer smokes (docs/consumers.md).
-gates: version-guard-local fmt-check build test-rust test-protocol test-runtime test-wasi test-sockets-node test-ct-runner test-bundle test-version-guard publish-check test-npm examples test-translate conformance sched-seeds shells browsers smoke-tls smoke-c0
+gates: version-guard-local fmt-check lint build test-rust test-protocol test-runtime test-wasi test-sockets-node test-ct-runner test-bundle test-version-guard publish-check test-npm examples test-translate conformance sched-seeds shells browsers smoke-tls smoke-c0
 
 # Fast sanity: builds + native tests + type-checks, no suites.
-check: fmt-check build test-rust
+check: fmt-check lint build test-rust
     cd protocol && deno task check
     cd runtime && deno task check
     cd wasi && deno task check
@@ -22,6 +22,11 @@ check: fmt-check build test-rust
 fmt-check:
     cd runtime && deno fmt --check
 
+# The runtime package is lint-clean (`deno lint`, stock rules; generated
+# artifacts excluded in runtime/deno.json alongside fmt).
+lint:
+    cd runtime && deno lint
+
 # ----- builders ---------------------------------------------------------------
 
 build:
diff --git a/runtime/deno.json b/runtime/deno.json
index f0ec766..69feffd 100644
--- a/runtime/deno.json
+++ b/runtime/deno.json
@@ -20,6 +20,13 @@
       "tests/fixtures/"
     ]
   },
+  "lint": {
+    "exclude": [
+      "tests/bindgen/generated/",
+      "tests/bindgen/fixtures/",
+      "tests/fixtures/"
+    ]
+  },
   "publish": {
     "exclude": [
       "tests/"
diff --git a/runtime/src/cabi/lift.ts b/runtime/src/cabi/lift.ts
index e057470..88c49a1 100644
--- a/runtime/src/cabi/lift.ts
+++ b/runtime/src/cabi/lift.ts
@@ -1,7 +1,7 @@
 // Flat lifting (definitions.py `## Flat Lifting`): core values -> component
 // values.
 
-import { assert_, NotImplemented, trapIf } from "./trap.ts";
+import { assert_, trapIf } from "./trap.ts";
 import {
   canonicalizeNan32,
   canonicalizeNan64,
diff --git a/runtime/src/cabi/load.ts b/runtime/src/cabi/load.ts
index 4af19f2..740ef06 100644
--- a/runtime/src/cabi/load.ts
+++ b/runtime/src/cabi/load.ts
@@ -1,6 +1,6 @@
 // Loading component values from linear memory (definitions.py `## Loading`).
 
-import { assert_, NotImplemented, trapIf } from "./trap.ts";
+import { assert_, trapIf } from "./trap.ts";
 import { bytesOf, loadIntS, loadIntU, loadPtr } from "./memory.ts";
 import { decodeI32AsFloat, decodeI64AsFloat } from "./float.ts";
 import { elemSizeFlags, layoutOf } from "./layout.ts";
@@ -8,12 +8,7 @@ import { convertI32ToChar, loadString } from "./strings.ts";
 import { type LiftLowerContext, requireMemory } from "./context.ts";
 import { tryLoadNumericList } from "./bulk_lists.ts";
 import { liftBorrow, liftOwn } from "./handles.ts";
-import {
-  type CaseType,
-  type ComponentValue,
-  type FieldType,
-  type ValType,
-} from "./types.ts";
+import type { CaseType, ComponentValue, FieldType, ValType } from "./types.ts";
 import { liftErrorContext, liftFuture, liftStream } from "./async_values.ts";
 
 export const MAX_LIST_BYTE_LENGTH = (1 << 28) - 1;
diff --git a/runtime/src/cabi/lower.ts b/runtime/src/cabi/lower.ts
index ddcb257..ba953cd 100644
--- a/runtime/src/cabi/lower.ts
+++ b/runtime/src/cabi/lower.ts
@@ -1,7 +1,7 @@
 // Flat lowering (definitions.py `## Flat Lowering`): component values ->
 // core values.
 
-import { assert_, NotImplemented } from "./trap.ts";
+import { assert_ } from "./trap.ts";
 import {
   encodeFloatAsI32,
   encodeFloatAsI64,
diff --git a/runtime/src/cabi/store.ts b/runtime/src/cabi/store.ts
index 5c97378..c798804 100644
--- a/runtime/src/cabi/store.ts
+++ b/runtime/src/cabi/store.ts
@@ -1,6 +1,6 @@
 // Storing component values into linear memory (definitions.py `## Storing`).
 
-import { assert_, NotImplemented, trapIf } from "./trap.ts";
+import { assert_, trapIf } from "./trap.ts";
 import { bytesOf, storeInt, storePtr } from "./memory.ts";
 import { tryStoreNumericList } from "./bulk_lists.ts";
 import { encodeFloatAsI32, encodeFloatAsI64 } from "./float.ts";
diff --git a/runtime/src/digest/digest.ts b/runtime/src/digest/digest.ts
index 1932e06..1cda659 100644
--- a/runtime/src/digest/digest.ts
+++ b/runtime/src/digest/digest.ts
@@ -215,7 +215,7 @@ function canonExportItem(
 }
 
 function canonFuncType(
-  plan: WirePlan,
+  _plan: WirePlan,
   decl: WireTypeDecl,
   resourceNames: Map<number, string>,
 ): Canon {
diff --git a/runtime/src/embedder/instantiate.ts b/runtime/src/embedder/instantiate.ts
index c8befee..0efc286 100644
--- a/runtime/src/embedder/instantiate.ts
+++ b/runtime/src/embedder/instantiate.ts
@@ -41,7 +41,6 @@ import { type ImportLeaf, requiredImports } from "./imports.ts";
 import { hostDtorCall } from "../exec/boundary.ts";
 import {
   buildGuestResourceClass,
-  type ExportWrapper,
   type GuestResourceSpec,
   HostResourceRegistry,
   invalidateWrapper,
@@ -59,7 +58,7 @@ import {
 } from "./values.ts";
 import { ImportResolver } from "./version.ts";
 import { type ElemCodec, Future, Stream } from "./streams.ts";
-import { markSyncCallable, syncPayloadOf } from "./sync.ts";
+import { markSyncCallable } from "./sync.ts";
 
 /**
  * Preserve declaration-level suspension/cancellation marks through every
@@ -404,59 +403,58 @@ class Facade {
   // -- the value bridge ------------------------------------------------------
 
   #makeBridge(): ValueBridge {
-    const self = this;
     return {
-      liftOwn(rep, t) {
-        const b = self.#binding(t.rt.resource);
+      liftOwn: (rep, t) => {
+        const b = this.#binding(t.rt.resource);
         // Host-implemented R: "the host's own instance back; the guest's
         // handle is gone; no dispose call" (contract 2x4 table).
         if (b.kind === "host") return b.registry.release(rep);
-        return makeWrapper(self.#guestClass(b), rep, t.rt.resource, true);
+        return makeWrapper(this.#guestClass(b), rep, t.rt.resource, true);
       },
-      liftBorrow(rep, t, scope) {
-        const b = self.#binding(t.rt.resource);
+      liftBorrow: (rep, t, scope) => {
+        const b = this.#binding(t.rt.resource);
         // Host-implemented R: "the host's own instance; borrow scoping is
         // guest-side bookkeeping" — the mapping is kept.
         if (b.kind === "host") return b.registry.lookup(rep);
-        const w = makeWrapper(self.#guestClass(b), rep, t.rt.resource, false);
+        const w = makeWrapper(this.#guestClass(b), rep, t.rt.resource, false);
         scope.add(() => invalidateWrapper(w));
         return w;
       },
-      lowerOwn(v, t) {
-        const b = self.#binding(t.rt.resource);
+      lowerOwn: (v, t) => {
+        const b = this.#binding(t.rt.resource);
         if (b.kind === "host") return b.registry.repFor(v);
         return takeRep(v, t.rt.resource, true, `own<${b.name}>`);
       },
-      lowerBorrow(v, t) {
-        const b = self.#binding(t.rt.resource);
+      lowerBorrow: (v, t) => {
+        const b = this.#binding(t.rt.resource);
         if (b.kind === "host") {
           // Each overlapping call retains the rep; the final borrow release
           // removes only temporary mappings, never a guest-owned registration.
           const { rep, release } = b.registry.borrowFor(v);
-          if (self.#lowerScope === null) release();
-          else self.#lowerScope.push(release);
+          if (this.#lowerScope === null) release();
+          else this.#lowerScope.push(release);
           return rep;
         }
         // Retain the rep until this call ends; explicit/GC drop must not
         // destroy it while borrowed (lift_borrow -> Subtask.add_lender).
         const rep = takeRep(v, t.rt.resource, false, `borrow<${b.name}>`);
         const release = lendWrapper(v as object);
-        if (self.#lowerScope === null) {
+        if (this.#lowerScope === null) {
           // No enclosing lowering scope (a raw/one-off lowering): the lend
           // has no observable window, so it must not be left dangling.
           release();
         } else {
-          self.#lowerScope.push(release);
+          this.#lowerScope.push(release);
         }
         return rep;
       },
-      dropOwn(rep, t) {
+      dropOwn: (rep, t) => {
         // resource stream: a lowered `own` the guest will never take (an un-taken
         // stream element). Destroy it exactly as a guest-side drop would:
         // host-implemented R runs the instance's [Symbol.dispose] through
         // the registry; guest-implemented R runs the guest dtor via the
         // gated path (a host-initiated drop, `caller = None`).
-        const b = self.#binding(t.rt.resource);
+        const b = this.#binding(t.rt.resource);
         if (b.kind === "host") {
           b.registry.dtor(rep);
           return;
@@ -825,7 +823,6 @@ class Facade {
     return out;
   }
 
-  // deno-lint-ignore no-explicit-any
   #buildInterface(
     id: string,
     exps: WireExport[],
@@ -1014,9 +1011,11 @@ class Facade {
     } catch (e) {
       try {
         release();
-      } finally {
-        throw e;
+      } catch {
+        // The original error wins; a secondary failure of the unwind is
+        // not the story.
       }
+      throw e;
     } finally {
       this.#lowerScope = outer;
     }
diff --git a/runtime/src/embedder/resources.ts b/runtime/src/embedder/resources.ts
index f052408..4704ac1 100644
--- a/runtime/src/embedder/resources.ts
+++ b/runtime/src/embedder/resources.ts
@@ -349,18 +349,22 @@ export function buildGuestResourceClass(
       } catch (e) {
         try {
           release();
-        } finally {
-          throw e;
+        } catch {
+          // The original error wins; a secondary failure of the unwind is
+          // not the story.
         }
+        throw e;
       }
       try {
         release();
       } catch (e) {
         try {
           if (typeof rep === "number") hostDtorCall(rt, rep);
-        } finally {
-          throw e;
+        } catch {
+          // The original error wins; a secondary failure of the unwind is
+          // not the story.
         }
+        throw e;
       }
       if (rep !== null && typeof rep === "object" && "then" in rep) {
         throw new TypeError(
diff --git a/runtime/src/embedder/streams.ts b/runtime/src/embedder/streams.ts
index 7788819..46c3db0 100644
--- a/runtime/src/embedder/streams.ts
+++ b/runtime/src/embedder/streams.ts
@@ -23,7 +23,7 @@ import {
 import {
   CopyResult,
   dropSharedForTeardown,
-  ErrorContext as InternalErrorContext,
+  type ErrorContext as InternalErrorContext,
   poisonFailureOf,
 } from "../task/mod.ts";
 import {
@@ -365,18 +365,17 @@ export class Stream<T> implements ProtocolStream<T> {
 
   /** Web-native view: `ReadableStream<Chunk<T>>`. */
   readable(): ReadableStream<Chunk<T>> {
-    const self = this;
     return new ReadableStream<Chunk<T>>({
-      async pull(controller) {
-        const chunk = await self.read(READ_CHUNK);
+      pull: async (controller) => {
+        const chunk = await this.read(READ_CHUNK);
         if ((chunk as { length: number }).length === 0) {
           controller.close();
           return;
         }
         controller.enqueue(chunk);
       },
-      cancel() {
-        self.drop();
+      cancel: () => {
+        this.drop();
       },
     });
   }
diff --git a/runtime/src/exec/boundary.ts b/runtime/src/exec/boundary.ts
index 2e146ce..4650fcd 100644
--- a/runtime/src/exec/boundary.ts
+++ b/runtime/src/exec/boundary.ts
@@ -20,7 +20,7 @@ import {
   MAX_FLAT_RESULTS,
   type MemInst,
   type PtrType,
-  ResourceTypeInfo,
+  type ResourceTypeInfo,
   trap,
   trapIf,
 } from "../cabi/mod.ts";
@@ -29,7 +29,7 @@ import {
   addInstancePoisonedListener,
   type BlockRequest,
   type Cancelled,
-  ComponentInstanceState,
+  type ComponentInstanceState,
   driveSyncLift,
   entryRefusal,
   EventCode,
@@ -42,7 +42,7 @@ import {
   packSubtaskResult,
   PendingCapability,
   realHostCalls,
-  Store,
+  type Store,
   storeQuiescent,
   Subtask,
   SubtaskState,
diff --git a/runtime/src/exec/executor.ts b/runtime/src/exec/executor.ts
index c8fa674..59f1c04 100644
--- a/runtime/src/exec/executor.ts
+++ b/runtime/src/exec/executor.ts
@@ -9,7 +9,7 @@
 //     ops (contracts/intrinsics.md)
 //   - component hash verification against plan.component
 
-import type { ComponentValue, FuncType, ValType } from "../cabi/types.ts";
+import type { FuncType, ValType } from "../cabi/types.ts";
 import { Trap } from "../cabi/trap.ts";
 import { ComponentInstanceState, Store } from "../task/mod.ts";
 import {
@@ -27,7 +27,6 @@ import {
   trampolineNeedsSuspension,
 } from "../jspi/mod.ts";
 import { loadPlan, PlanError, resourceIndexOfDefined } from "../plan/loader.ts";
-import { PendingCapability } from "../task/mod.ts";
 import type {
   WireCanonicalOptions,
   WireCoreDef,
diff --git a/runtime/src/intrinsics/async_builtins.ts b/runtime/src/intrinsics/async_builtins.ts
index d2d280d..2717dd0 100644
--- a/runtime/src/intrinsics/async_builtins.ts
+++ b/runtime/src/intrinsics/async_builtins.ts
@@ -37,9 +37,8 @@ import {
   liftOptionsEqual,
   needsJspi,
   Subtask,
-  SubtaskState,
   type Task,
-  Thread,
+  type Thread,
   Waitable,
   WaitableSet,
 } from "../task/mod.ts";
diff --git a/runtime/src/intrinsics/fact_calls.ts b/runtime/src/intrinsics/fact_calls.ts
index 2623fb2..75abc9c 100644
--- a/runtime/src/intrinsics/fact_calls.ts
+++ b/runtime/src/intrinsics/fact_calls.ts
@@ -56,7 +56,7 @@ import type { CoreValue, FuncType, ValType } from "../cabi/types.ts";
 import {
   type BlockRequest,
   type Cancelled,
-  ComponentInstanceState,
+  type ComponentInstanceState,
   currentTask,
   entryRefusal,
   maybeCurrentTask,
@@ -814,12 +814,11 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
diff --git a/runtime/src/intrinsics/mod.ts b/runtime/src/intrinsics/mod.ts
index 0774834..26957bb 100644
--- a/runtime/src/intrinsics/mod.ts
+++ b/runtime/src/intrinsics/mod.ts
@@ -14,12 +14,7 @@ import { trapIf } from "../cabi/trap.ts";
 import { assert_ } from "../cabi/trap.ts";
 import type { ResourceTableInfo } from "../cabi/types.ts";
 import type { ComponentInstanceState } from "../task/mod.ts";
-import {
-  dbgId,
-  entryRefusal,
-  maybeCurrentTask,
-  maybeCurrentThread,
-} from "../task/mod.ts";
+import { dbgId, entryRefusal, maybeCurrentThread } from "../task/mod.ts";
 import type { WireTrampoline } from "../plan/format.ts";
 import type { CoreFn, ExecutionStats } from "../exec/boundary.ts";
 import { UnsupportedFeatureError } from "./errors.ts";
@@ -334,7 +329,6 @@ function declaredInstance(
   return ctx.componentInstance(instance);
 }
 
-// deno-lint-ignore no-explicit-any
 const SCOPE_TRACE = (() => {
   try {
     return Deno.env.get("CE_SCOPE_TRACE") === "1";
@@ -347,9 +341,9 @@ const SCOPE_TRACE = (() => {
  * Brackets belong to the running thread because activations can interleave.
  * Instantiation-time start functions have no thread and use the executor stack.
  */
-function syncScopes(ctx: TrampolineContext, site = "?"): any[] {
+function syncScopes(ctx: TrampolineContext, site = "?"): SyncCallScope[] {
   const thread = maybeCurrentThread() as
-    | { syncCallStack: any[] }
+    | { syncCallStack: SyncCallScope[] }
     | undefined;
   const scopes = thread?.syncCallStack ?? ctx.syncCallStack;
   if (SCOPE_TRACE) {
diff --git a/runtime/src/intrinsics/stream_builtins.ts b/runtime/src/intrinsics/stream_builtins.ts
index 06e453f..ec16b08 100644
--- a/runtime/src/intrinsics/stream_builtins.ts
+++ b/runtime/src/intrinsics/stream_builtins.ts
@@ -28,7 +28,7 @@ import {
   abandonReasonOf,
   BUFFER_MAX_LENGTH,
   type ComponentInstanceState,
-  CopyEnd,
+  type CopyEnd,
   CopyResult,
   CopyState,
   currentInstance,
diff --git a/runtime/src/task/scheduler.ts b/runtime/src/task/scheduler.ts
index eb5f2ae..aaa008d 100644
--- a/runtime/src/task/scheduler.ts
+++ b/runtime/src/task/scheduler.ts
@@ -489,7 +489,6 @@ export function maybeCurrentThread(): CurrentThreadLike | undefined {
  * the brackets and claims. In definitions.py `canon_context_get` and
  * `canon_context_set`, identity comes directly from `current_thread`.
  */
-// deno-lint-ignore no-explicit-any
 export function currentThreadForInstance<T = CurrentThreadLike>(
   inst: unknown,
 ): T {
diff --git a/runtime/src/task/streams.ts b/runtime/src/task/streams.ts
index 0a0d13c..67acf92 100644
--- a/runtime/src/task/streams.ts
+++ b/runtime/src/task/streams.ts
@@ -10,7 +10,7 @@
 
 import { defineBrand, ERROR_CONTEXT } from "@polyengine/protocol";
 import { assert_, Trap, trapIf } from "../cabi/trap.ts";
-import { LiftLowerContext } from "../cabi/context.ts";
+import type { LiftLowerContext } from "../cabi/context.ts";
 import { bytesOf } from "../cabi/memory.ts";
 import { loadListFromValidRange } from "../cabi/load.ts";
 import { storeListIntoValidRange } from "../cabi/store.ts";
diff --git a/runtime/tests/async_builtins_test.ts b/runtime/tests/async_builtins_test.ts
index 57df1b6..b863ccc 100644
--- a/runtime/tests/async_builtins_test.ts
+++ b/runtime/tests/async_builtins_test.ts
@@ -20,6 +20,7 @@ import {
   createStreamNew,
   createStreamRead,
   createStreamWrite,
+  type StreamTrampolineContext,
 } from "../src/intrinsics/stream_builtins.ts";
 import {
   createLiftedFunction,
@@ -348,16 +349,14 @@ Deno.test("stream.cancel-write supersedes an undelivered COMPLETED", () => {
 
   // deno-lint-ignore no-explicit-any
   const newStream = createStreamNew({ streamTable: 0 }, ctx as any, inst);
-  // deno-lint-ignore no-explicit-any
   const write = createStreamWrite(
     { streamTable: 0, options: 0 },
-    ctx as any,
+    ctx as unknown as StreamTrampolineContext,
     inst,
   );
-  // deno-lint-ignore no-explicit-any
   const read = createStreamRead(
     { streamTable: 0, options: 0 },
-    ctx as any,
+    ctx as unknown as StreamTrampolineContext,
     inst,
   );
   const cancelWrite = createStreamCancelWrite(
diff --git a/runtime/tests/builtin_index_normalization_test.ts b/runtime/tests/builtin_index_normalization_test.ts
index 15a8abe..e313b21 100644
--- a/runtime/tests/builtin_index_normalization_test.ts
+++ b/runtime/tests/builtin_index_normalization_test.ts
@@ -43,7 +43,6 @@ import {
   Store,
   Task,
   Thread,
-  WaitableSet,
 } from "../src/task/mod.ts";
 import type { ResolvedOptions } from "../src/exec/boundary.ts";
 
diff --git a/runtime/tests/conventions/error_context_test.ts b/runtime/tests/conventions/error_context_test.ts
index 371be9f..91562d9 100644
--- a/runtime/tests/conventions/error_context_test.ts
+++ b/runtime/tests/conventions/error_context_test.ts
@@ -102,7 +102,7 @@ Deno.test({
   name:
     "conventions/g: isErrorContext accepts a hand-rolled carrier, rejects a husk",
   fn: async () => {
-    await transcript("g-error-context-predicate", async (t) => {
+    await transcript("g-error-context-predicate", (t) => {
       // The vocabulary claim on its own: recognition is brand + string
       // `message`, in any copy, hand-rolled or not.
       t.note("hand-rolled", {
@@ -113,6 +113,7 @@ Deno.test({
       husk[Symbol.for(ERROR_CONTEXT_KEY)] = true;
       t.note("branded-non-string-message", { classified: classify(husk) });
       t.note("unbranded", { classified: classify({ message: "m" }) });
+      return Promise.resolve();
     });
   },
 });
diff --git a/runtime/tests/conventions/errors_test.ts b/runtime/tests/conventions/errors_test.ts
index ffb137f..5aea922 100644
--- a/runtime/tests/conventions/errors_test.ts
+++ b/runtime/tests/conventions/errors_test.ts
@@ -17,7 +17,7 @@
 // predicate. Trap MESSAGE text is diagnostic, not API — an engine-worded trap
 // (a raw `unreachable`) is recorded by brand alone (see support.ts).
 
-import { guest, haveFixture, instantiateFixture, testdata } from "./harness.ts";
+import { guest, haveFixture, instantiateFixture } from "./harness.ts";
 import { transcript } from "./support.ts";
 import { classify, ComponentException } from "./probe.ts";
 import { handRolledException } from "./probe_zero_import.ts";
@@ -143,7 +143,7 @@ Deno.test({
   name:
     "conventions/e: predicates recognize a hand-rolled exception, either copy",
   fn: async () => {
-    await transcript("e-brand-recognition", async (t) => {
+    await transcript("e-brand-recognition", (t) => {
       // No engine involved: the vocabulary claim itself. A hand-rolled brand
       // and the canonical class are the same thing to every predicate, because
       // the brand is a `Symbol.for` registry symbol.
@@ -157,6 +157,7 @@ Deno.test({
       // A payloadless err: `payload` is `undefined`, and the property is
       // PRESENT (the empty-side spelling), which normalize() records.
       t.note("payloadless", { value: new ComponentException(undefined) });
+      return Promise.resolve();
     });
   },
 });
diff --git a/runtime/tests/embedder/future_result_test.ts b/runtime/tests/embedder/future_result_test.ts
index db40a48..0ebb023 100644
--- a/runtime/tests/embedder/future_result_test.ts
+++ b/runtime/tests/embedder/future_result_test.ts
@@ -16,14 +16,14 @@ import { caught, guest, haveFixture, instantiateFixture } from "./support.ts";
 import {
   Future,
   lowerFutureSource,
-  Stream,
+  type Stream,
 } from "../../src/embedder/streams.ts";
 import { hostFuture, hostFutureFor } from "../../src/exec/host_streams.ts";
-import { HostResourceRegistry } from "../../src/embedder/resources.ts";
+import type { HostResourceRegistry } from "../../src/embedder/resources.ts";
 import { INTERNAL_HOST_REGISTRIES } from "../../src/embedder/instantiate.ts";
 import { sync } from "../../src/embedder/sync.ts";
 import { StreamProducerError, Trap } from "@polyengine/protocol";
-import { SharedFutureImpl } from "../../src/task/mod.ts";
+import type { SharedFutureImpl } from "../../src/task/mod.ts";
 
 const turn = () => new Promise<void>((resolve) => setTimeout(resolve, 0));
 const ownFixture = "runtime/tests/embedder/future-own.wasm";
@@ -218,8 +218,8 @@ for (const synchronous of [false, true]) {
           toHost: (v) => v as number,
           fromHost: (v) => v,
         });
-        let registry: HostResourceRegistry;
-        let rep: number;
+        // Forward reference: the closure runs later, after `registry`/`rep`
+        // below are filled in.
         const c = await instantiateFixture(cleanupFixture, {
           r: R,
           next: () => future,
@@ -228,12 +228,12 @@ for (const synchronous of [false, true]) {
             if (callFails) throw primary;
           },
         });
-        registry =
+        const registry =
           (c as unknown as Record<symbol, Map<number, HostResourceRegistry>>)[
             INTERNAL_HOST_REGISTRIES
           ].get(0)!;
         const cell = new R();
-        rep = registry.repFor(cell);
+        const rep = registry.repFor(cell);
         let observed: unknown;
         try {
           await (synchronous ? sync(c.exports.run)(cell) : c.exports.run(cell));
diff --git a/runtime/tests/embedder/host_imports_test.ts b/runtime/tests/embedder/host_imports_test.ts
index b482ae6..f3e61ac 100644
--- a/runtime/tests/embedder/host_imports_test.ts
+++ b/runtime/tests/embedder/host_imports_test.ts
@@ -358,8 +358,8 @@ for (const mode of ["constructor", "promise", "sync"] as const) {
           throw boom;
         }
       }
-      let registry: HostResourceRegistry;
-      let rep: number;
+      // Forward reference: the closure runs later, after `registry`/`rep`
+      // below are filled in.
       const c = await instantiateFixture(overlapFixture, {
         "host:api/res": {
           R,
@@ -369,12 +369,12 @@ for (const mode of ["constructor", "promise", "sync"] as const) {
           },
         },
       });
-      registry =
+      const registry =
         (c as unknown as Record<symbol, Map<number, HostResourceRegistry>>)[
           INTERNAL_HOST_REGISTRIES
         ].get(0)!;
       const cell = new R();
-      rep = registry.repFor(cell);
+      const rep = registry.repFor(cell);
       const e = await caught(() =>
         mode === "constructor"
           ? new c.exports.Ticket(cell)
@@ -405,8 +405,8 @@ for (const mode of ["constructor", "promise", "sync"] as const) {
           throw new Error("secondary disposal");
         }
       }
-      let registry: HostResourceRegistry;
-      let rep: number;
+      // Forward reference: the closure runs later, after `registry`/`rep`
+      // below are filled in.
       const c = await instantiateFixture(overlapFixture, {
         "host:api/res": {
           R,
@@ -416,12 +416,12 @@ for (const mode of ["constructor", "promise", "sync"] as const) {
           },
         },
       });
-      registry =
+      const registry =
         (c as unknown as Record<symbol, Map<number, HostResourceRegistry>>)[
           INTERNAL_HOST_REGISTRIES
         ].get(0)!;
       const cell = new R();
-      rep = registry.repFor(cell);
+      const rep = registry.repFor(cell);
       const e = await caught(() =>
         mode === "constructor"
           ? new c.exports.Ticket(cell)
@@ -617,7 +617,7 @@ Deno.test({
       symbol,
       Map<number, HostResourceRegistry>
     >)[INTERNAL_HOST_REGISTRIES].get(0)!;
-    using ticket = new c.exports.Ticket(cell);
+    using _ticket = new c.exports.Ticket(cell);
     assertEq(seen === cell, true);
     assertEq(registry.liveCount, 0);
   },
diff --git a/runtime/tests/embedder/platform_class_test.ts b/runtime/tests/embedder/platform_class_test.ts
index e7a6dd5..5390429 100644
--- a/runtime/tests/embedder/platform_class_test.ts
+++ b/runtime/tests/embedder/platform_class_test.ts
@@ -25,7 +25,7 @@
 
 import { assertEq } from "../support/asserts.ts";
 import { caught, haveFixture, instantiateFixture } from "./support.ts";
-import { ComponentException, isTrap, Trap } from "@polyengine/protocol";
+import { ComponentException, isTrap } from "@polyengine/protocol";
 
 const FIXTURE = "runtime/tests/embedder/platform-class.wasm";
 const ready = await haveFixture(FIXTURE);
diff --git a/runtime/tests/entry_deferral_test.ts b/runtime/tests/entry_deferral_test.ts
index d782d02..fdd2692 100644
--- a/runtime/tests/entry_deferral_test.ts
+++ b/runtime/tests/entry_deferral_test.ts
@@ -79,13 +79,10 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
 
diff --git a/runtime/tests/fact_call_test.ts b/runtime/tests/fact_call_test.ts
index a1565ce..8433fc1 100644
--- a/runtime/tests/fact_call_test.ts
+++ b/runtime/tests/fact_call_test.ts
@@ -17,9 +17,13 @@ import { assertEq } from "./support/asserts.ts";
 import {
   createAsyncStartCall,
   createPrepareCall,
+  type FactCallContext,
   type PreparedCall,
 } from "../src/intrinsics/fact_calls.ts";
-import { createTaskReturn } from "../src/intrinsics/async_builtins.ts";
+import {
+  type AsyncTrampolineContext,
+  createTaskReturn,
+} from "../src/intrinsics/async_builtins.ts";
 import { newStats, type ResolvedOptions } from "../src/exec/boundary.ts";
 import {
   ComponentInstanceState,
@@ -94,12 +98,13 @@ function runPrepared(input: {
       ? input.calleeResults[0]
       : input.calleeResults;
 
-  // deno-lint-ignore no-explicit-any
-  const prep = createPrepareCall({ memory: null }, ctx as any);
-  // deno-lint-ignore no-explicit-any
+  const prep = createPrepareCall(
+    { memory: null },
+    ctx as unknown as FactCallContext,
+  );
   const startCall = createAsyncStartCall(
     { callback: null, postReturn: null },
-    ctx as any,
+    ctx as unknown as FactCallContext,
   );
 
   prep(
@@ -214,12 +219,11 @@ Deno.test("FACT: task.return preserves float lanes on the passthrough", () => {
     // plan v3: `results` = raw wasmtime TypeTupleIndex, `resultType` = the
     // interned plan.types entry (here: the empty tuple, type 0).
     { results: 0, resultType: 0, options: 0 },
-    // deno-lint-ignore no-explicit-any
     {
       componentInstance: () => inst,
       options: () => opts,
       resultTypes: () => [],
-    } as any,
+    } as unknown as AsyncTrampolineContext,
   );
   const thread = new Thread(task, (function* () {})());
   pushCurrentThread(thread);
diff --git a/runtime/tests/host_import_cancel_test.ts b/runtime/tests/host_import_cancel_test.ts
index b275e97..5b5b6bf 100644
--- a/runtime/tests/host_import_cancel_test.ts
+++ b/runtime/tests/host_import_cancel_test.ts
@@ -39,7 +39,7 @@ import {
   popCurrentThread,
   pushCurrentThread,
   Store,
-  Subtask,
+  type Subtask,
   SubtaskState,
   Task,
   type TaskOptions,
diff --git a/runtime/tests/integration/e2e_async_test.ts b/runtime/tests/integration/e2e_async_test.ts
index 437c7ab..1e969be 100644
--- a/runtime/tests/integration/e2e_async_test.ts
+++ b/runtime/tests/integration/e2e_async_test.ts
@@ -18,8 +18,7 @@
 import { assertEq } from "../support/asserts.ts";
 import { Translator } from "../../src/shim/mod.ts";
 import { instantiateComponent } from "../../src/exec/mod.ts";
-import { PendingCapability } from "../../src/task/mod.ts";
-import { AssertionError, NotImplemented, Trap } from "../../src/cabi/mod.ts";
+import { AssertionError } from "../../src/cabi/mod.ts";
 
 function assert(cond: boolean, msg: string): asserts cond {
   if (!cond) throw new Error(`assertion failed: ${msg}`);
diff --git a/runtime/tests/park_state_settle_test.ts b/runtime/tests/park_state_settle_test.ts
index 6d2679c..538b725 100644
--- a/runtime/tests/park_state_settle_test.ts
+++ b/runtime/tests/park_state_settle_test.ts
@@ -53,7 +53,7 @@ import type { SuspensionPoint } from "../src/jspi/mod.ts";
 import {
   canonResourceDrop,
   canonResourceNew,
-  ResourceHandle,
+  type ResourceHandle,
   ResourceTableInfo,
   ResourceTypeInfo,
 } from "../src/cabi/mod.ts";
diff --git a/runtime/tests/resource_identity_test.ts b/runtime/tests/resource_identity_test.ts
index 6842a27..47a99b9 100644
--- a/runtime/tests/resource_identity_test.ts
+++ b/runtime/tests/resource_identity_test.ts
@@ -6,7 +6,7 @@ import {
   canonResourceNew,
   canonResourceRep,
   LiftLowerContext,
-  ResourceHandle,
+  type ResourceHandle,
   ResourceTableInfo,
   ResourceTypeInfo,
   Trap,
@@ -33,7 +33,7 @@ import {
 } from "../src/exec/boundary.ts";
 import {
   ComponentInstanceState,
-  CopyEnd,
+  type CopyEnd,
   CopyState,
   popCurrentThread,
   pushCurrentThread,
diff --git a/runtime/tests/resource_lender_park_settle_test.ts b/runtime/tests/resource_lender_park_settle_test.ts
index 4cdf8b4..a4ed2ad 100644
--- a/runtime/tests/resource_lender_park_settle_test.ts
+++ b/runtime/tests/resource_lender_park_settle_test.ts
@@ -33,6 +33,7 @@ import {
   createAsyncStartCall,
   createPrepareCall,
   createSyncStartCall,
+  type FactCallContext,
   type PreparedCall,
 } from "../src/intrinsics/fact_calls.ts";
 import type { FactStartScope } from "../src/intrinsics/mod.ts";
@@ -46,7 +47,7 @@ import type { SuspensionPoint } from "../src/jspi/mod.ts";
 import {
   canonResourceDrop,
   canonResourceNew,
-  ResourceHandle,
+  type ResourceHandle,
   ResourceTableInfo,
   ResourceTypeInfo,
 } from "../src/cabi/mod.ts";
@@ -130,15 +131,18 @@ function mkHarness(): Harness {
       };
       const return_ = () => undefined as unknown as CoreValue;
 
-      // deno-lint-ignore no-explicit-any
-      const prep = createPrepareCall({ memory: null }, ctx as any);
+      const prep = createPrepareCall(
+        { memory: null },
+        ctx as unknown as FactCallContext,
+      );
       const startCall = kind === "sync"
-        // deno-lint-ignore no-explicit-any
-        ? createSyncStartCall({ callback: null }, ctx as any)
-        // deno-lint-ignore no-explicit-any
+        ? createSyncStartCall(
+          { callback: null },
+          ctx as unknown as FactCallContext,
+        )
         : createAsyncStartCall(
           { callback: null, postReturn: null },
-          ctx as any,
+          ctx as unknown as FactCallContext,
         );
 
       prep(
diff --git a/runtime/tests/resource_lender_unwind_test.ts b/runtime/tests/resource_lender_unwind_test.ts
index 471714b..45528d7 100644
--- a/runtime/tests/resource_lender_unwind_test.ts
+++ b/runtime/tests/resource_lender_unwind_test.ts
@@ -24,7 +24,7 @@ import { NeedsJspi } from "../src/task/scheduler.ts";
 import {
   canonResourceDrop,
   canonResourceNew,
-  ResourceHandle,
+  type ResourceHandle,
   ResourceTableInfo,
   ResourceTypeInfo,
 } from "../src/cabi/mod.ts";
diff --git a/runtime/tests/settled_deferral_test.ts b/runtime/tests/settled_deferral_test.ts
index 96da05d..84be3bb 100644
--- a/runtime/tests/settled_deferral_test.ts
+++ b/runtime/tests/settled_deferral_test.ts
@@ -34,13 +34,12 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
 
diff --git a/runtime/tests/settlement_pump_test.ts b/runtime/tests/settlement_pump_test.ts
index e328a39..0c0a52d 100644
--- a/runtime/tests/settlement_pump_test.ts
+++ b/runtime/tests/settlement_pump_test.ts
@@ -24,10 +24,6 @@ import { assertEq } from "./support/asserts.ts";
 import { driveStoreAsync } from "../src/exec/mod.ts";
 import { markHostActivityArm, Store } from "../src/task/mod.ts";
 
-function assert(cond: boolean, msg: string): asserts cond {
-  if (!cond) throw new Error(`assertion failed: ${msg}`);
-}
-
 /** The slice of `ComponentInstance` that `Store.tick` touches. */
 function fakeInst() {
   return {};
diff --git a/runtime/tests/stale_cancellable_flag_test.ts b/runtime/tests/stale_cancellable_flag_test.ts
index eda2f2d..536aa25 100644
--- a/runtime/tests/stale_cancellable_flag_test.ts
+++ b/runtime/tests/stale_cancellable_flag_test.ts
@@ -33,13 +33,12 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
 
diff --git a/runtime/tests/streams_teardown_test.ts b/runtime/tests/streams_teardown_test.ts
index 0cff7fb..d0ed4ad 100644
--- a/runtime/tests/streams_teardown_test.ts
+++ b/runtime/tests/streams_teardown_test.ts
@@ -736,7 +736,7 @@ Deno.test("#100: a host peer parked on a poisoned guest's end is still notified"
 
 for (const future of [false, true]) {
   for (const writable of [false, true]) {
-    Deno.test(`removed busy ${future ? "future" : "stream"} ${writable ? "writer" : "reader"} cannot copy stale guest bytes`, async () => {
+    Deno.test(`removed busy ${future ? "future" : "stream"} ${writable ? "writer" : "reader"} cannot copy stale guest bytes`, () => {
       const inst = new ComponentInstanceState(0, new Store());
       const { memory, view } = mkMemory();
       const u8 = { kind: "u8" } as const;
diff --git a/runtime/tests/suspension_point_pending_cancel_test.ts b/runtime/tests/suspension_point_pending_cancel_test.ts
index a2a355b..ba50aa6 100644
--- a/runtime/tests/suspension_point_pending_cancel_test.ts
+++ b/runtime/tests/suspension_point_pending_cancel_test.ts
@@ -45,13 +45,12 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
 
diff --git a/runtime/tests/task_test.ts b/runtime/tests/task_test.ts
index 35213cc..cf3de9e 100644
--- a/runtime/tests/task_test.ts
+++ b/runtime/tests/task_test.ts
@@ -85,13 +85,12 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }
 
diff --git a/runtime/tests/wait_until_pending_cancel_test.ts b/runtime/tests/wait_until_pending_cancel_test.ts
index b2e4351..294ba4d 100644
--- a/runtime/tests/wait_until_pending_cancel_test.ts
+++ b/runtime/tests/wait_until_pending_cancel_test.ts
@@ -42,13 +42,12 @@ function spawn(
   task: Task,
   body: (t: Thread) => Generator<BlockRequest, void, Cancelled>,
 ): Thread {
-  let thread!: Thread;
-  thread = new Thread(
-    task,
-    (function* (): Generator<BlockRequest, void, Cancelled> {
-      yield* body(thread);
-    })(),
-  );
+  // Forward reference: the generator body only runs once `thread` below
+  // is assigned (spawn returns before the body executes).
+  function* threadBody(): Generator<BlockRequest, void, Cancelled> {
+    yield* body(thread);
+  }
+  const thread: Thread = new Thread(task, threadBody());
   return thread;
 }