refactor: consolidate getPayload + deploymentTarget onto src/lib

Two divergent getPayload entries existed: src/lib/getPayload.ts (thin, raw
Payload Local API) and src/plugins/payload-runtime/getPayload.ts (194 lines: a
deepUuidWrap Proxy + initializePlatformBackends). The Proxy was a no-op
(deepUuidWrap returns its input unchanged) and the platform-backend singletons
(getCacheBackend/getStorageBackend/getImageTransformer) are read only by unit
tests, so the two entries were behaviorally identical for every runtime path.

- Migrate the 10 payload-runtime/getPayload importers (+ the jest.mock path) onto
  @root/lib/getPayload; drop the no-op Proxy and the dead backend bootstrap.
- The two deploymentTarget copies differed only in formatting / relative-import
  depth; migrate the 2 payload-runtime/deploymentTarget importers onto
  @root/lib/deploymentTarget.
- Remove the now-empty src/plugins/payload-runtime/ directory.
- Note in lib/cache + lib/storage that the backend init is no longer auto-invoked.

Verified: tsc 0; dev server boots and serves home/admin/post (200, seeded
content). Tests not run — jest config is broken under ESM (pre-existing, tracked
separately).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ceccec

src/__tests__/integration/api/stripe.test.ts

@@ -10,15 +10,15 @@ import { NextRequest } from 'next/server'
 /**
  * Mock Payload and Stripe modules
  */
-jest.mock('@root/plugins/payload-runtime/getPayload', () => ({
+jest.mock('@root/lib/getPayload', () => ({
   getPayload: jest.fn(),
 }))
 
 jest.mock('@root/plugins/site-billing/marketingCheckout', () => ({
   createMarketingCheckout: jest.fn(),
 }))
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import { createMarketingCheckout } from '@root/plugins/site-billing/marketingCheckout'
 
 /**

src/app/(frontend)/(cloud)/cloud/_actions/paymentActions.ts

@@ -13,7 +13,7 @@
  * ```
  */
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import type { SetupIntentResponse, SubscriptionResponse } from '@root/plugins/payments'
 import { getPaymentProvider } from '@root/plugins/payments'
 import {

src/app/api/docs-local-search/route.ts

@@ -1,4 +1,4 @@
-import { getDeploymentTarget } from '@root/plugins/payload-runtime/deploymentTarget'
+import { getDeploymentTarget } from '@root/lib/deploymentTarget'
 import { execFile } from 'node:child_process'
 import fs from 'node:fs'
 import path from 'node:path'

src/app/api/preview/route.ts

@@ -1,7 +1,7 @@
 import type { NextRequest } from 'next/server'
 import type { PayloadRequest } from 'payload'
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import { draftMode } from 'next/headers'
 import { redirect } from 'next/navigation'
 

src/app/api/share/[token]/route.ts

@@ -1,6 +1,6 @@
 import type { NextRequest } from 'next/server'
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import { formatPagePath } from '@root/utilities/formatPagePath'
 import { NextResponse } from 'next/server'
 

src/app/api/stripe/billing-portal/route.ts

@@ -1,7 +1,7 @@
 import type { NextRequest } from 'next/server'
 import type { PayloadRequest } from 'payload'
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import { createMarketingBillingSession } from '@root/plugins/site-billing/marketingBilling'
 import { NextResponse } from 'next/server'
 

src/app/api/stripe/checkout-session/route.ts

@@ -1,7 +1,7 @@
 import type { NextRequest } from 'next/server'
 import type { PayloadRequest } from 'payload'
 
-import { getPayload } from '@root/plugins/payload-runtime/getPayload'
+import { getPayload } from '@root/lib/getPayload'
 import { createMarketingCheckout } from '@root/plugins/site-billing/marketingCheckout'
 import { NextResponse } from 'next/server'
 

src/lib/cache/index.ts

@@ -142,8 +142,11 @@ export class MemoryCacheBackend implements CacheBackend {
 let globalCacheBackend: CacheBackend | null = null
 
 /**
- * Initialize the global cache backend
- * Called during app startup in src/plugins/payload-runtime/getPayload.ts
+ * Initialize the global cache backend.
+ *
+ * Not currently auto-invoked: the platform-backend bootstrap was removed when the two getPayload
+ * entries were consolidated onto `@root/lib/getPayload`. Nothing in the app reads this backend yet
+ * (only unit tests) — call this explicitly once a consumer is wired up.
  */
 export function initializeCacheBackend(backend: CacheBackend): void {
   globalCacheBackend = backend

src/lib/storage/index.ts

@@ -208,8 +208,11 @@ export class MemoryStorageBackend implements StorageBackend {
 let globalStorageBackend: StorageBackend | null = null
 
 /**
- * Initialize the global storage backend
- * Called during app startup in src/plugins/payload-runtime/getPayload.ts
+ * Initialize the global storage backend.
+ *
+ * Not currently auto-invoked: the platform-backend bootstrap was removed when the two getPayload
+ * entries were consolidated onto `@root/lib/getPayload`. Nothing in the app reads this backend yet
+ * (only unit tests) — call this explicitly once a consumer is wired up.
  */
 export function initializeStorageBackend(backend: StorageBackend): void {
   globalStorageBackend = backend

src/platform/types.ts

@@ -1,4 +1,4 @@
-import type { DeploymentTarget } from '@root/plugins/payload-runtime/deploymentTarget'
+import type { DeploymentTarget } from '@root/lib/deploymentTarget'
 import type { TypedLocale } from 'payload'
 
 /**