test(mobile): share the recorder's fixture helper instead of copying it into eight adapters

The seam forbids one adapter importing another, not an adapter importing the engine, and the
adapters already take `hookMount` and `observableModel` from there. So the eight byte-identical
copies of `mountFixture` bought nothing: eight doc comments and eight cast suppressions for one
four-line function that has no per-domain part.

Export it from `recorder-fixture-shape.ts`, next to the type it checks against, and leave one
suppression instead of nine. `adapter-seam.test.ts` 7/7 and `pnpm --dir mobile typecheck` stay clean.

Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb

mobile/src/test-support/rpc-recording/adapters/task-item-checks-status-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -141,17 +141,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-item-conversation-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -161,17 +161,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-item-hosted-metadata-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -159,17 +159,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-list-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -28,17 +28,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-project-board-load-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -120,17 +120,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-project-row-comment-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -120,17 +120,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-project-row-field-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -126,17 +126,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/adapters/task-project-row-merge-mount-adapters.ts

@@ -2,7 +2,7 @@ import { hookMount, performHookAction } from '../hook-mount'
 import { observableModel, projectObservable } from '../observable-model'
 import type { MountAdapter, MountContext, MountedOperation } from '../recording-scenario'
 import type { operationModuleLoader } from '../operation-module-loader'
-import type { PartialRecorderFixture } from '../recorder-fixture-shape'
+import { mountFixture } from '../recorder-fixture-shape'
 
 const REPO_ID = 'repo-1'
 
@@ -150,17 +150,6 @@ type ModelHookSpec<Actions> = {
   readonly state: (model: Record<string, unknown>) => Record<string, unknown>
 }
 
-/**
- * The recorder supplies only the members the mounted action reads; completing the fixture into a
- * full domain object would invent data no scenario observes. `NoInfer` makes the target the
- * parameter's type rather than the fixture's, so a member the real type does not have is an error
- * here instead of a silently wrong recording.
- */
-function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
-  return value as T
-}
-
 function mountModelHook<Actions>(
   context: MountContext,
   spec: ModelHookSpec<Actions>

mobile/src/test-support/rpc-recording/recorder-fixture-shape.ts

@@ -4,11 +4,10 @@
  * type. That is what a mount fixture actually is — deliberately partial, because it carries only
  * what the mounted hook reads, yet still a subset of the real thing.
  *
- * Type-only, and here rather than outside the recorder because `mobile/scripts/rpc-recording.mts`
- * fences every path under `mobile/src` except this directory, so a file outside it fails recording
- * as an unpinned product source. It sits in the engine rather than under `adapters/` because the
- * mount helper that uses it is copied per module and the seam forbids one module importing another,
- * so this is what stops eleven copies of a recursive conditional type from existing.
+ * Here rather than outside the recorder because `mobile/scripts/rpc-recording.mts` fences every
+ * path under `mobile/src` except this directory, so a file outside it fails recording as an unpinned
+ * product source. In the engine rather than under `adapters/` because the seam forbids one adapter
+ * importing another, and every adapter may import the engine.
  *
  * Functions pass through whole: a fixture stub like `async () => 0` stands in for a callback, and
  * making its parameters optional would accept a stub the hook cannot call.
@@ -26,3 +25,14 @@ export type PartialRecorderFixture<T> = T extends (...args: never[]) => unknown
       : T extends object
         ? { readonly [Key in keyof T]?: PartialRecorderFixture<T[Key]> | null }
         : T
+
+/**
+ * The recorder supplies only the members the mounted action reads; completing the fixture into a
+ * full domain object would invent data no scenario observes. `NoInfer` makes the target the
+ * parameter's type rather than the fixture's, so a member the real type does not have is an error
+ * here instead of a silently wrong recording.
+ */
+export function mountFixture<T>(value: PartialRecorderFixture<NoInfer<T>>): T {
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: checked as a deep subset of T above; the recorder supplies every member the action reads.
+  return value as T
+}