diff --git a/Frontend/PROGRESS.md b/Frontend/PROGRESS.md
index 8e8075d..3bdc995 100644
--- a/Frontend/PROGRESS.md
+++ b/Frontend/PROGRESS.md
@@ -5,14 +5,18 @@ Spec: `docs/20-FRONTEND.md` (flows + rules) · `docs/11-BACKEND-PHASE1.md` (API
 Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit** as the code. When ticking `[x]`, append a short note + any deviation.
 
 ## 0. Foundation
-- [x] `NEXT_PUBLIC_API_BASE_URL` wired (`.env.local` / `.env.local.example`, alongside the existing `NEXT_PUBLIC_AUTH_API_BASE_URL`) — points at `Backend/ERPCore`'s https profile (`7112`)
-- [x] Typed API client / fetch wrapper (`lib/api-client.ts`: `apiRequest`/`apiRequestWithETag`/`buildQuery`) + bearer token handling (`lib/auth-token.ts`, degrades gracefully — no login endpoint wired yet, see §1)
-- [x] Shared TS types mirroring API DTOs (`types/common.ts`, `types/master-data.ts`, `types/procurement.ts`, `types/grn.ts`) — built only for the subset GRN needs (Item/Warehouse/Bin/Vendor/Uom/PurchaseOrder/Grn)
+- [x] `NEXT_PUBLIC_API_BASE_URL` wired (`.env.local` / `.env.local.example`, alongside the existing `NEXT_PUBLIC_AUTH_API_BASE_URL`) — currently unused now that the fetch client is gone (see 2026-07-15 note below)
+- [ ] Typed API client / fetch wrapper — **removed 2026-07-15** (`lib/api-client.ts` + `lib/auth-token.ts` deleted per explicit user request: "delete all api connections"). No live code path in the frontend makes an HTTP call to any backend anymore — every screen is 100% mock data (`lib/api/mock-data.ts`).
+- [x] Shared TS types mirroring API DTOs (`types/common.ts`, `types/master-data.ts`, `types/procurement.ts`, `types/grn.ts`) — built only for the subset GRN needs (Item/Warehouse/Bin/Vendor/Uom/PurchaseOrder/Grn); `types/common.ts` now also carries `ApiResult<T>` (moved here 2026-07-15 when `lib/api-client.ts` was deleted, since it's a plain data envelope, not fetch-specific)
 - [~] Client validation helpers (`lib/validations/grn.ts`) — **deviation**: uses `zod` (already a project dependency, used by `lib/validations.ts`/login), not hand-rolled, to stay consistent with the codebase's existing pattern rather than introduce a second validation approach. UX-only; server remains authoritative (docs/20-FRONTEND.md §3)
-- [x] `ProblemDetails` normalizer (`ApiError` in `lib/api-client.ts`) + `code → message` map (`lib/error-map.ts`)
+- [x] `code → message` map (`lib/error-map.ts`) — `errorMessage`/`fieldErrors` duck-type any `{ code, detail, errors }`-shaped rejection (the `ApiError` class they used to check via `instanceof` no longer exists); this also fixed a latent bug where the mock layer's plain `Error`-plus-`.code` rejects never matched the old `instanceof ApiError` check, so `CODE_MESSAGES` silently never applied to any mock error
 
 > **Scope note:** this foundation was built alongside the GRN feature and only covers the endpoints GRN consumes (items, warehouses/bins, vendors, uoms, purchase-orders, grns). Other master-data/procurement API methods still need their own `lib/api/*.ts` files when those screens are built.
 
+> **2026-07-15 — fetch infrastructure deleted outright (not just reverted to mock).** Following an earlier same-week pass that wired every `lib/api/*.ts` module to real `fetch` calls (then reverted via `git revert --no-commit` at the user's request — see `Backend`-adjacent history if relevant later), the user asked to go further and delete the underlying connection mechanism entirely, not just leave it unused. Deleted `lib/api-client.ts` (`apiRequest`/`apiRequestWithETag`/`buildQuery`/`ApiError`) and `lib/auth-token.ts` (bearer-token storage) as files. Follow-on fixes this required: (1) `ApiResult<T>` — used by `items.ts`/`purchase-orders.ts`/`vendors.ts` for their mock ETag pattern — moved into `types/common.ts`; (2) `lib/error-map.ts` rewritten to duck-type instead of `instanceof ApiError`; (3) three detail pages (`vendors/[id]`, `products/[id]`, `procurement/purchase-orders/[id]`) had their `err instanceof ApiError ? err.code : (err as {code?:string})?.code` conflict-detection simplified to the duck-typed form only. Also stripped the now-dangling commented-out "real implementation" blocks (`// import { apiRequest... } from "@/lib/api-client"` etc.) from all 15 `lib/api/*.ts` files, since they referenced a now-deleted module. `tsc --noEmit`/`eslint` clean (same pre-existing `login/page.tsx` error and established `set-state-in-effect` pattern only — confirmed unchanged by this pass).
+>
+> **If real backend integration is attempted again**, note two things found during the reverted pass: the RFQ backend contract had drifted from this file's assumed shapes (`Backend/ERPCore/Dtos/Procurement/RfqDtos.cs`/`RfqService.cs` — no persisted invited-vendor list, `requisitionId` required on create, different comparison DTO field names) — re-verify against the actual backend rather than trusting old assumptions; and a typed fetch client + ETag/error-normalization layer will need to be rebuilt from scratch since `lib/api-client.ts`/`lib/auth-token.ts` no longer exist.
+
 ## 1. Auth
 - [~] Login screen — UI built (`app/login`); not yet wired to `POST /auth/login` / token storage
 - [~] Forgot password — add email screen — UI built (`app/login/forgot`); not yet wired to API
diff --git a/Frontend/erp-system/app/dashboard/procurement/purchase-orders/[id]/page.tsx b/Frontend/erp-system/app/dashboard/procurement/purchase-orders/[id]/page.tsx
index 8b0be76..a205486 100644
--- a/Frontend/erp-system/app/dashboard/procurement/purchase-orders/[id]/page.tsx
+++ b/Frontend/erp-system/app/dashboard/procurement/purchase-orders/[id]/page.tsx
@@ -10,7 +10,6 @@ import { warehousesApi } from "@/lib/api/warehouses"
 import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { vendorsApi } from "@/lib/api/vendors"
-import { ApiError } from "@/lib/api-client"
 import { errorMessage } from "@/lib/error-map"
 import { validatePoLine } from "@/lib/validations/procurement"
 import { cn } from "@/lib/utils"
@@ -172,7 +171,7 @@ export default function PurchaseOrderDetailPage() {
       setLines(toDraftLines(result.data))
       toast.success("Purchase order saved", `${result.data.docNo} updated (FR-PROC-05, edit-while-open).`)
     } catch (err) {
-      const code = err instanceof ApiError ? err.code : (err as { code?: string })?.code
+      const code = (err as { code?: string })?.code
       if (code === "CONCURRENCY_CONFLICT") {
         setConflict(true)
         setSaveError(errorMessage(err))
diff --git a/Frontend/erp-system/app/dashboard/products/[id]/page.tsx b/Frontend/erp-system/app/dashboard/products/[id]/page.tsx
index a319060..94cd29d 100644
--- a/Frontend/erp-system/app/dashboard/products/[id]/page.tsx
+++ b/Frontend/erp-system/app/dashboard/products/[id]/page.tsx
@@ -10,7 +10,6 @@ import { categoriesApi } from "@/lib/api/categories"
 import { uomsApi } from "@/lib/api/uoms"
 import { vendorsApi } from "@/lib/api/vendors"
 import { warehousesApi } from "@/lib/api/warehouses"
-import { ApiError } from "@/lib/api-client"
 import { errorMessage, fieldErrors } from "@/lib/error-map"
 import { validateConversionLine, validateItemForm, validateReorderLine } from "@/lib/validations/master-data"
 import { cn } from "@/lib/utils"
@@ -147,7 +146,7 @@ export default function ItemDetailPage() {
       setEtag(result.etag)
       toast.success("Item saved", `${result.data.sku} — ${result.data.name}`)
     } catch (err) {
-      const code = err instanceof ApiError ? err.code : (err as { code?: string })?.code
+      const code = (err as { code?: string })?.code
       if (code === "CONCURRENCY_CONFLICT") {
         setConflict(true)
         setSaveError(errorMessage(err))
diff --git a/Frontend/erp-system/app/dashboard/vendors/[id]/page.tsx b/Frontend/erp-system/app/dashboard/vendors/[id]/page.tsx
index 6e3e256..b04f997 100644
--- a/Frontend/erp-system/app/dashboard/vendors/[id]/page.tsx
+++ b/Frontend/erp-system/app/dashboard/vendors/[id]/page.tsx
@@ -6,7 +6,6 @@ import Link from "next/link"
 import { AlertTriangle, ArrowLeft, Save } from "lucide-react"
 
 import { vendorsApi } from "@/lib/api/vendors"
-import { ApiError } from "@/lib/api-client"
 import { errorMessage, fieldErrors } from "@/lib/error-map"
 import { cn } from "@/lib/utils"
 import { Vendor } from "@/types/master-data"
@@ -78,7 +77,7 @@ export default function VendorDetailPage() {
       setEtag(result.etag)
       toast.success("Vendor saved", `${result.data.code} — ${result.data.name}`)
     } catch (err) {
-      const code = err instanceof ApiError ? err.code : (err as { code?: string })?.code
+      const code = (err as { code?: string })?.code
       if (code === "CONCURRENCY_CONFLICT") {
         setConflict(true)
         setSaveError(errorMessage(err))
diff --git a/Frontend/erp-system/lib/api-client.ts b/Frontend/erp-system/lib/api-client.ts
deleted file mode 100644
index f0e3098..0000000
--- a/Frontend/erp-system/lib/api-client.ts
+++ /dev/null
@@ -1,98 +0,0 @@
-// Single typed fetch client for the ERPCore API (docs/20-FRONTEND.md §1: "A single
-// typed fetch client against NEXT_PUBLIC_API_BASE_URL; all calls go through it. No
-// scattered fetch() in components."). Per-endpoint methods live in lib/api/*.ts.
-import { ProblemDetails } from "@/types/common"
-import { getAccessToken } from "@/lib/auth-token"
-
-const API_BASE = `${process.env.NEXT_PUBLIC_API_BASE_URL ?? ""}/api/v1`
-
-/** Normalized RFC 7807 error (docs/11-BACKEND-PHASE1.md §1.8) thrown on any non-2xx response. */
-export class ApiError extends Error {
-  status: number
-  code?: string
-  detail?: string
-  errors?: Record<string, string[]>
-  traceId?: string
-
-  constructor(problem: ProblemDetails) {
-    super(problem.title || "Request failed")
-    this.status = problem.status
-    this.code = problem.code
-    this.detail = problem.detail
-    this.errors = problem.errors
-    this.traceId = problem.traceId
-  }
-}
-
-export interface RequestOptions extends Omit<RequestInit, "body"> {
-  body?: unknown
-  /** Sent as If-Match for concurrency-guarded PUT/PATCH (docs/11 §1.6). */
-  ifMatch?: string
-  /** Sent as Idempotency-Key for transactional POSTs (e.g. GRN confirm, docs/11 §1.6). */
-  idempotencyKey?: string
-}
-
-export interface ApiResult<T> {
-  data: T
-  /** Response ETag header, when the resource is mutable (docs/11 §1.6). */
-  etag: string | null
-}
-
-async function rawRequest(path: string, options: RequestOptions = {}): Promise<Response> {
-  const { body, ifMatch, idempotencyKey, headers, ...rest } = options
-  const token = getAccessToken()
-
-  const finalHeaders: Record<string, string> = {
-    Accept: "application/json",
-    ...(body !== undefined ? { "Content-Type": "application/json" } : {}),
-    ...(token ? { Authorization: `Bearer ${token}` } : {}),
-    ...(ifMatch ? { "If-Match": ifMatch } : {}),
-    ...(idempotencyKey ? { "Idempotency-Key": idempotencyKey } : {}),
-    ...((headers as Record<string, string> | undefined) ?? {}),
-  }
-
-  const response = await fetch(`${API_BASE}${path}`, {
-    ...rest,
-    headers: finalHeaders,
-    body: body !== undefined ? JSON.stringify(body) : undefined,
-  })
-
-  if (!response.ok) {
-    let problem: ProblemDetails
-    try {
-      problem = (await response.json()) as ProblemDetails
-    } catch {
-      problem = { title: response.statusText || "Request failed", status: response.status }
-    }
-    if (!problem.status) problem.status = response.status
-    throw new ApiError(problem)
-  }
-
-  return response
-}
-
-/** Fire a request and decode the JSON body only (no ETag needed). */
-export async function apiRequest<T>(path: string, options?: RequestOptions): Promise<T> {
-  const response = await rawRequest(path, options)
-  if (response.status === 204) return undefined as T
-  return (await response.json()) as T
-}
-
-/** Fire a request and also surface the ETag header, for resources that support If-Match. */
-export async function apiRequestWithETag<T>(path: string, options?: RequestOptions): Promise<ApiResult<T>> {
-  const response = await rawRequest(path, options)
-  const etag = response.headers.get("ETag")
-  const data = response.status === 204 ? (undefined as T) : ((await response.json()) as T)
-  return { data, etag }
-}
-
-/** Build a `?a=1&b=2` query string, dropping null/undefined/empty values. */
-export function buildQuery(params: object): string {
-  const search = new URLSearchParams()
-  for (const [key, value] of Object.entries(params) as [string, string | number | boolean | null | undefined][]) {
-    if (value === null || value === undefined || value === "") continue
-    search.set(key, String(value))
-  }
-  const qs = search.toString()
-  return qs ? `?${qs}` : ""
-}
diff --git a/Frontend/erp-system/lib/api/categories.ts b/Frontend/erp-system/lib/api/categories.ts
index 6602cc3..45c473a 100644
--- a/Frontend/erp-system/lib/api/categories.ts
+++ b/Frontend/erp-system/lib/api/categories.ts
@@ -1,29 +1,9 @@
 // One typed client method per Category endpoint (docs/11-BACKEND-PHASE1.md §2.3, FR-MD-04).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so these screens
-// can be reviewed without a running backend. Restore the commented block and
-// delete the mock block once Backend/PROGRESS.md §1 (Master Data) exists.
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { Category, CategoryTreeNode, CreateCategoryRequest } from "@/types/master-data"
 import { allocateCategoryId, mockCategories, mockDelay } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest } from "@/lib/api-client"
-//
-// export const categoriesApi = {
-//   list() {
-//     return apiRequest<PagedResponse<Category>>("/categories")
-//   },
-//   tree() {
-//     return apiRequest<CategoryTreeNode[]>("/categories?tree=true")
-//   },
-//   create(request: CreateCategoryRequest) {
-//     return apiRequest<Category>("/categories", { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 function buildTree(categories: Category[]): CategoryTreeNode[] {
   const nodes = new Map<number, CategoryTreeNode>(categories.map((c) => [c.categoryId, { ...c, children: [] }]))
   const roots: CategoryTreeNode[] = []
diff --git a/Frontend/erp-system/lib/api/grns.ts b/Frontend/erp-system/lib/api/grns.ts
index 8021ced..78757ec 100644
--- a/Frontend/erp-system/lib/api/grns.ts
+++ b/Frontend/erp-system/lib/api/grns.ts
@@ -1,12 +1,7 @@
 // One typed client method per GRN endpoint (docs/11-BACKEND-PHASE1.md §4).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with an in-memory mock store (lib/api/mock-data.ts) so the GRN
-// screens (list/create/confirm/release) can be reviewed end-to-end without a
-// running backend. Restore the commented block and delete the mock block once
-// Backend/PROGRESS.md §3/§4 (GRN + Stock Core) exist. Note GET /grns and
-// GET /grns/{id} are not yet in docs/11-BACKEND-PHASE1.md §4 — see the note in
-// Frontend/PROGRESS.md §4.
+// In-memory mock store (lib/api/mock-data.ts) — no backend API calls. Note
+// GET /grns and GET /grns/{id} are not in docs/11-BACKEND-PHASE1.md §4 — see
+// the note in Frontend/PROGRESS.md §4.
 import { PagedResponse } from "@/types/common"
 import {
   ConfirmGrnResponse,
@@ -20,60 +15,6 @@ import {
 } from "@/types/grn"
 import { allocateGrnId, allocateGrnLineId, mockDelay, mockGrns, mockPurchaseOrders, receiveLayer } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, apiRequestWithETag, buildQuery } from "@/lib/api-client"
-//
-// export interface ListGrnsParams {
-//   page?: number
-//   pageSize?: number
-//   q?: string
-//   status?: GrnStatus
-//   poId?: number
-//   warehouseId?: number
-// }
-//
-// export const grnsApi = {
-//   list(params: ListGrnsParams = {}) {
-//     return apiRequest<PagedResponse<GrnSummary>>(`/grns${buildQuery(params)}`)
-//   },
-//
-//   get(grnId: number) {
-//     return apiRequest<Grn>(`/grns/${grnId}`)
-//   },
-//
-//   async create(request: CreateGrnRequest) {
-//     const { data } = await apiRequestWithETag<Grn>("/grns", { method: "POST", body: request })
-//     return data
-//   },
-//
-//   // Draft-only — a GRN with createdLayers/ledger postings (Confirmed/Closed) is
-//   // immutable per docs/11 §4.
-//   async update(grnId: number, request: CreateGrnRequest, ifMatch: string) {
-//     const { data } = await apiRequestWithETag<Grn>(`/grns/${grnId}`, { method: "PUT", body: request, ifMatch })
-//     return data
-//   },
-//
-//   remove(grnId: number) {
-//     return apiRequest<void>(`/grns/${grnId}`, { method: "DELETE" })
-//   },
-//
-//   confirm(grnId: number, idempotencyKey?: string) {
-//     return apiRequest<ConfirmGrnResponse>(`/grns/${grnId}/confirm`, {
-//       method: "POST",
-//       body: {},
-//       idempotencyKey,
-//     })
-//   },
-//
-//   releaseLine(grnId: number, grnLineId: number, action: ReleaseAction) {
-//     return apiRequest<ReleaseGrnLineResponse>(`/grns/${grnId}/lines/${grnLineId}/release`, {
-//       method: "POST",
-//       body: { action },
-//     })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListGrnsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/items.ts b/Frontend/erp-system/lib/api/items.ts
index b1816bf..c31e1e9 100644
--- a/Frontend/erp-system/lib/api/items.ts
+++ b/Frontend/erp-system/lib/api/items.ts
@@ -1,12 +1,7 @@
 // One typed client method per Item endpoint (docs/11-BACKEND-PHASE1.md §2.1, FR-MD-01/05/08).
 // `list` also backs the GRN/PO/Requisition/RFQ item pickers built in earlier sessions.
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so these screens
-// can be reviewed without a running backend. Restore the commented block and
-// delete the mock block once Backend/PROGRESS.md §1 (Master Data) exists.
-import { ApiResult } from "@/lib/api-client"
-import { EntityStatus, PagedResponse } from "@/types/common"
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
+import { ApiResult, EntityStatus, PagedResponse } from "@/types/common"
 import {
   CreateItemRequest,
   Item,
@@ -26,43 +21,6 @@ import {
   mockItems,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, apiRequestWithETag, buildQuery } from "@/lib/api-client"
-//
-// export interface ListItemsParams {
-//   page?: number
-//   pageSize?: number
-//   q?: string
-//   status?: EntityStatus
-//   categoryId?: number
-//   trackingMode?: TrackingMode
-// }
-//
-// export const itemsApi = {
-//   list(params: ListItemsParams = {}) {
-//     return apiRequest<PagedResponse<ItemListItem>>(`/items${buildQuery(params)}`)
-//   },
-//   get(itemId: number) {
-//     return apiRequestWithETag<Item>(`/items/${itemId}`)
-//   },
-//   create(request: CreateItemRequest) {
-//     return apiRequestWithETag<Item>("/items", { method: "POST", body: request })
-//   },
-//   update(itemId: number, request: UpdateItemRequest, ifMatch: string) {
-//     return apiRequestWithETag<Item>(`/items/${itemId}`, { method: "PUT", body: request, ifMatch })
-//   },
-//   updateStatus(itemId: number, status: EntityStatus) {
-//     return apiRequest<void>(`/items/${itemId}/status`, { method: "PATCH", body: { status } })
-//   },
-//   updateReorder(itemId: number, request: UpdateItemReorderRequest) {
-//     return apiRequest<{ settings: UpdateItemReorderRequest["settings"] }>(`/items/${itemId}/reorder`, { method: "PUT", body: request })
-//   },
-//   updateUomConversions(itemId: number, request: UpdateUomConversionsRequest) {
-//     return apiRequest<UpdateUomConversionsResponse>(`/items/${itemId}/uom-conversions`, { method: "PUT", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListItemsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/mock-data.ts b/Frontend/erp-system/lib/api/mock-data.ts
index 46b46cd..fb35ae8 100644
--- a/Frontend/erp-system/lib/api/mock-data.ts
+++ b/Frontend/erp-system/lib/api/mock-data.ts
@@ -1,9 +1,6 @@
-// Temporary in-memory sample data so the GRN screens can be reviewed as pure UI
-// without a running backend. Shapes mirror docs/11-BACKEND-PHASE1.md exactly.
-//
-// This file (and the "MOCK" blocks in the sibling lib/api/*.ts files) is meant
-// to be deleted once the real GRN backend exists — the original fetch-based
-// implementations are left commented out in each file for that switch-back.
+// In-memory sample data backing every lib/api/*.ts module — the app has no
+// fetch-based backend connection (lib/api-client.ts and lib/auth-token.ts were
+// removed). Shapes mirror docs/11-BACKEND-PHASE1.md.
 import { Bin, Category, Item, Uom, Vendor, Warehouse } from "@/types/master-data"
 import { PurchaseOrder, Quotation, Requisition, Rfq, PurchaseReturn } from "@/types/procurement"
 import { Grn } from "@/types/grn"
diff --git a/Frontend/erp-system/lib/api/purchase-orders.ts b/Frontend/erp-system/lib/api/purchase-orders.ts
index 50ea6fa..791d2b5 100644
--- a/Frontend/erp-system/lib/api/purchase-orders.ts
+++ b/Frontend/erp-system/lib/api/purchase-orders.ts
@@ -1,13 +1,7 @@
 // One typed client method per Purchase Order endpoint (docs/11-BACKEND-PHASE1.md §3.3,
 // FR-PROC-03..07). `get`/`list` also back the GRN "against a PO" picker.
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so the GRN and
-// Procurement screens can be reviewed without a running backend. Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §2/§3/§4
-// (Procurement + GRN + Stock Core) exist.
-import { ApiResult } from "@/lib/api-client"
-import { PagedResponse } from "@/types/common"
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
+import { ApiResult, PagedResponse } from "@/types/common"
 import {
   CancelPurchaseOrderRequest,
   CreatePurchaseOrderRequest,
@@ -25,39 +19,6 @@ import {
   mockPurchaseOrders,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, apiRequestWithETag, buildQuery } from "@/lib/api-client"
-//
-// export interface ListPurchaseOrdersParams {
-//   page?: number
-//   pageSize?: number
-//   q?: string
-//   status?: PurchaseOrderStatus
-//   vendorId?: number
-// }
-//
-// export const purchaseOrdersApi = {
-//   list(params: ListPurchaseOrdersParams = {}) {
-//     return apiRequest<PagedResponse<PurchaseOrderSummary>>(`/purchase-orders${buildQuery(params)}`)
-//   },
-//   get(poId: number) {
-//     return apiRequest<PurchaseOrder>(`/purchase-orders/${poId}`)
-//   },
-//   getWithETag(poId: number) {
-//     return apiRequestWithETag<PurchaseOrder>(`/purchase-orders/${poId}`)
-//   },
-//   create(request: CreatePurchaseOrderRequest) {
-//     return apiRequestWithETag<PurchaseOrder>("/purchase-orders", { method: "POST", body: request })
-//   },
-//   update(poId: number, request: UpdatePurchaseOrderRequest, ifMatch: string) {
-//     return apiRequestWithETag<PurchaseOrder>(`/purchase-orders/${poId}`, { method: "PUT", body: request, ifMatch })
-//   },
-//   cancel(poId: number, request: CancelPurchaseOrderRequest) {
-//     return apiRequest<PurchaseOrder>(`/purchase-orders/${poId}/cancel`, { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListPurchaseOrdersParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/purchase-returns.ts b/Frontend/erp-system/lib/api/purchase-returns.ts
index 248262c..10fb0a1 100644
--- a/Frontend/erp-system/lib/api/purchase-returns.ts
+++ b/Frontend/erp-system/lib/api/purchase-returns.ts
@@ -1,9 +1,5 @@
 // One typed client method per Purchase Return endpoint (docs/11-BACKEND-PHASE1.md §3.4, FR-PROC-08).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so the Procurement
-// screens can be reviewed without a running backend. Restore the commented block
-// and delete the mock block once Backend/PROGRESS.md §2 (Procurement) exists.
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { CreatePurchaseReturnRequest, PurchaseReturn, PurchaseReturnSummary } from "@/types/procurement"
 import {
@@ -15,22 +11,6 @@ import {
   postLedgerEntry,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest } from "@/lib/api-client"
-//
-// export const purchaseReturnsApi = {
-//   list() {
-//     return apiRequest<PagedResponse<PurchaseReturnSummary>>("/purchase-returns")
-//   },
-//   get(returnId: number) {
-//     return apiRequest<PurchaseReturn>(`/purchase-returns/${returnId}`)
-//   },
-//   create(request: CreatePurchaseReturnRequest) {
-//     return apiRequest<PurchaseReturn>("/purchase-returns", { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 function toSummary(r: PurchaseReturn): PurchaseReturnSummary {
   return {
     returnId: r.returnId,
diff --git a/Frontend/erp-system/lib/api/reason-codes.ts b/Frontend/erp-system/lib/api/reason-codes.ts
index 0274f38..bd1c301 100644
--- a/Frontend/erp-system/lib/api/reason-codes.ts
+++ b/Frontend/erp-system/lib/api/reason-codes.ts
@@ -1,21 +1,9 @@
 // One typed client method for reference data (docs/11-BACKEND-PHASE1.md §6).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts).
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { ReasonCode, ReasonCodeContext } from "@/types/stock"
 import { mockDelay, mockReasonCodes } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export const reasonCodesApi = {
-//   list(context?: ReasonCodeContext) {
-//     return apiRequest<PagedResponse<ReasonCode>>(`/reason-codes${buildQuery({ context })}`)
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export const reasonCodesApi = {
   list(context?: ReasonCodeContext): Promise<PagedResponse<ReasonCode>> {
     const items = mockReasonCodes.filter((r) => !context || r.context === context)
diff --git a/Frontend/erp-system/lib/api/requisitions.ts b/Frontend/erp-system/lib/api/requisitions.ts
index 9442ff3..01a9954 100644
--- a/Frontend/erp-system/lib/api/requisitions.ts
+++ b/Frontend/erp-system/lib/api/requisitions.ts
@@ -1,38 +1,9 @@
 // One typed client method per Requisition endpoint (docs/11-BACKEND-PHASE1.md §3.1, FR-PROC-01).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so the Procurement
-// screens can be reviewed without a running backend. Restore the commented block
-// and delete the mock block once Backend/PROGRESS.md §2 (Procurement) exists.
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { CreateRequisitionRequest, Requisition, RequisitionStatus, RequisitionSummary } from "@/types/procurement"
 import { allocateReqLineId, allocateRequisitionId, mockDelay, mockRequisitions } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export interface ListRequisitionsParams {
-//   page?: number
-//   pageSize?: number
-//   status?: RequisitionStatus
-// }
-//
-// export const requisitionsApi = {
-//   list(params: ListRequisitionsParams = {}) {
-//     return apiRequest<PagedResponse<RequisitionSummary>>(`/requisitions${buildQuery(params)}`)
-//   },
-//   get(requisitionId: number) {
-//     return apiRequest<Requisition>(`/requisitions/${requisitionId}`)
-//   },
-//   create(request: CreateRequisitionRequest) {
-//     return apiRequest<Requisition>("/requisitions", { method: "POST", body: request })
-//   },
-//   submit(requisitionId: number) {
-//     return apiRequest<Requisition>(`/requisitions/${requisitionId}/submit`, { method: "POST", body: {} })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListRequisitionsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/rfqs.ts b/Frontend/erp-system/lib/api/rfqs.ts
index b7380f7..e58416d 100644
--- a/Frontend/erp-system/lib/api/rfqs.ts
+++ b/Frontend/erp-system/lib/api/rfqs.ts
@@ -1,9 +1,5 @@
 // One typed client method per RFQ/Quotation endpoint (docs/11-BACKEND-PHASE1.md §3.2, FR-PROC-02).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so the Procurement
-// screens can be reviewed without a running backend. Restore the commented block
-// and delete the mock block once Backend/PROGRESS.md §2 (Procurement) exists.
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import {
   CreateQuotationRequest,
@@ -23,28 +19,6 @@ import {
   mockRfqs,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest } from "@/lib/api-client"
-//
-// export const rfqsApi = {
-//   list() {
-//     return apiRequest<PagedResponse<RfqSummary>>("/rfqs")
-//   },
-//   get(rfqId: number) {
-//     return apiRequest<Rfq>(`/rfqs/${rfqId}`)
-//   },
-//   create(request: CreateRfqRequest) {
-//     return apiRequest<Rfq>("/rfqs", { method: "POST", body: request })
-//   },
-//   addQuotation(rfqId: number, request: CreateQuotationRequest) {
-//     return apiRequest<Quotation>(`/rfqs/${rfqId}/quotations`, { method: "POST", body: request })
-//   },
-//   comparison(rfqId: number) {
-//     return apiRequest<RfqComparison>(`/rfqs/${rfqId}/comparison`)
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 function toSummary(r: Rfq): RfqSummary {
   return {
     rfqId: r.rfqId,
diff --git a/Frontend/erp-system/lib/api/stock-adjustments.ts b/Frontend/erp-system/lib/api/stock-adjustments.ts
index b48f118..d29a2fd 100644
--- a/Frontend/erp-system/lib/api/stock-adjustments.ts
+++ b/Frontend/erp-system/lib/api/stock-adjustments.ts
@@ -1,11 +1,5 @@
 // One typed client method per adjustment endpoint (docs/11-BACKEND-PHASE1.md §5.5).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with the in-memory Stock Core (lib/api/mock-data.ts). Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §5
-// (stock transactions) exists. GET /stock-adjustments and GET
-// /stock-adjustments/{id} are not documented in docs/11 §5.5 — same
-// assumed-extension deviation as GRN (see Frontend/PROGRESS.md §5).
+// In-memory Stock Core (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { AdjustmentStatus, CreateAdjustmentRequest, StockAdjustment, StockAdjustmentSummary } from "@/types/stock"
 import {
@@ -19,28 +13,6 @@ import {
   receiveLayer,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export interface ListAdjustmentsParams {
-//   page?: number
-//   pageSize?: number
-//   warehouseId?: number
-// }
-//
-// export const stockAdjustmentsApi = {
-//   list(params: ListAdjustmentsParams = {}) {
-//     return apiRequest<PagedResponse<StockAdjustmentSummary>>(`/stock-adjustments${buildQuery(params)}`)
-//   },
-//   get(adjustmentId: number) {
-//     return apiRequest<StockAdjustment>(`/stock-adjustments/${adjustmentId}`)
-//   },
-//   create(request: CreateAdjustmentRequest) {
-//     return apiRequest<StockAdjustment>("/stock-adjustments", { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListAdjustmentsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/stock-counts.ts b/Frontend/erp-system/lib/api/stock-counts.ts
index a2427f6..21f280e 100644
--- a/Frontend/erp-system/lib/api/stock-counts.ts
+++ b/Frontend/erp-system/lib/api/stock-counts.ts
@@ -1,11 +1,5 @@
 // One typed client method per count endpoint (docs/11-BACKEND-PHASE1.md §5.6).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with the in-memory Stock Core (lib/api/mock-data.ts). Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §5
-// (stock transactions) exists. GET /stock-counts and GET /stock-counts/{id}
-// are not documented in docs/11 §5.6 — same assumed-extension deviation as
-// GRN (see Frontend/PROGRESS.md §5).
+// In-memory Stock Core (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import {
   CountStatus,
@@ -31,34 +25,6 @@ import {
   receiveLayer,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export interface ListCountsParams {
-//   page?: number
-//   pageSize?: number
-//   warehouseId?: number
-// }
-//
-// export const stockCountsApi = {
-//   list(params: ListCountsParams = {}) {
-//     return apiRequest<PagedResponse<StockCountSummary>>(`/stock-counts${buildQuery(params)}`)
-//   },
-//   get(countId: number) {
-//     return apiRequest<StockCount>(`/stock-counts/${countId}`)
-//   },
-//   create(request: CreateCountRequest) {
-//     return apiRequest<StockCount>("/stock-counts", { method: "POST", body: request })
-//   },
-//   enterCounts(countId: number, request: EnterCountsRequest) {
-//     return apiRequest<EnterCountsResponse>(`/stock-counts/${countId}/counts`, { method: "PUT", body: request })
-//   },
-//   post(countId: number) {
-//     return apiRequest<PostCountResponse>(`/stock-counts/${countId}/post`, { method: "POST", body: {} })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListCountsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/stock-transfers.ts b/Frontend/erp-system/lib/api/stock-transfers.ts
index b6c1552..80e515a 100644
--- a/Frontend/erp-system/lib/api/stock-transfers.ts
+++ b/Frontend/erp-system/lib/api/stock-transfers.ts
@@ -1,11 +1,5 @@
 // One typed client method per transfer endpoint (docs/11-BACKEND-PHASE1.md §5.4).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with the in-memory Stock Core (lib/api/mock-data.ts). Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §5
-// (stock transactions) exists. GET /stock-transfers and GET /stock-transfers/{id}
-// are not documented in docs/11 §5.4 — same assumed-extension deviation as GRN
-// (see Frontend/PROGRESS.md §5).
+// In-memory Stock Core (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import {
   CreateTransferRequest,
@@ -27,39 +21,6 @@ import {
   receiveLayer,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export interface ListTransfersParams {
-//   page?: number
-//   pageSize?: number
-//   status?: TransferStatus
-//   srcWarehouseId?: number
-//   destWarehouseId?: number
-// }
-//
-// export const stockTransfersApi = {
-//   list(params: ListTransfersParams = {}) {
-//     return apiRequest<PagedResponse<StockTransferSummary>>(`/stock-transfers${buildQuery(params)}`)
-//   },
-//   get(transferId: number) {
-//     return apiRequest<StockTransfer>(`/stock-transfers/${transferId}`)
-//   },
-//   create(request: CreateTransferRequest) {
-//     return apiRequest<StockTransfer>("/stock-transfers", { method: "POST", body: request })
-//   },
-//   dispatch(transferId: number) {
-//     return apiRequest<DispatchTransferResponse>(`/stock-transfers/${transferId}/dispatch`, { method: "POST", body: {} })
-//   },
-//   receive(transferId: number, lines: ReceiveTransferLineInput[]) {
-//     return apiRequest<ReceiveTransferResponse>(`/stock-transfers/${transferId}/receive`, {
-//       method: "POST",
-//       body: { lines },
-//     })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListTransfersParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/stock.ts b/Frontend/erp-system/lib/api/stock.ts
index 58d31be..130983b 100644
--- a/Frontend/erp-system/lib/api/stock.ts
+++ b/Frontend/erp-system/lib/api/stock.ts
@@ -1,10 +1,5 @@
 // One typed client method per stock-enquiry endpoint (docs/11-BACKEND-PHASE1.md §5.1-5.3, §5.7).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with the in-memory Stock Core (lib/api/mock-data.ts) so the Stock
-// Management screens can be reviewed without a running backend. Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §4
-// (Stock Core) exists.
+// In-memory Stock Core (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { LedgerEntry, OnHand, ReorderAlert, ReorderRequisitionResponse, Valuation } from "@/types/stock"
 import {
@@ -19,44 +14,6 @@ import {
   mockStockLedger,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, buildQuery } from "@/lib/api-client"
-//
-// export interface LedgerQuery {
-//   itemId?: number
-//   warehouseId?: number
-//   from?: string
-//   to?: string
-//   page?: number
-//   pageSize?: number
-// }
-//
-// export const stockApi = {
-//   onHand(itemId: number, warehouseId: number) {
-//     return apiRequest<OnHand>(`/stock/on-hand${buildQuery({ itemId, warehouseId })}`)
-//   },
-//
-//   ledger(params: LedgerQuery) {
-//     return apiRequest<PagedResponse<LedgerEntry>>(`/stock/ledger${buildQuery(params)}`)
-//   },
-//
-//   valuation(itemId: number, warehouseId: number) {
-//     return apiRequest<Valuation>(`/stock/valuation${buildQuery({ itemId, warehouseId })}`)
-//   },
-//
-//   reorderAlerts(warehouseId?: number) {
-//     return apiRequest<PagedResponse<ReorderAlert>>(`/stock/reorder-alerts${buildQuery({ warehouseId })}`)
-//   },
-//
-//   createReorderRequisition(itemId: number, warehouseId: number) {
-//     return apiRequest<ReorderRequisitionResponse>(
-//       `/stock/reorder-alerts/${itemId}/requisition${buildQuery({ warehouseId })}`,
-//       { method: "POST", body: {} }
-//     )
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface LedgerQuery {
   itemId?: number
   warehouseId?: number
diff --git a/Frontend/erp-system/lib/api/uoms.ts b/Frontend/erp-system/lib/api/uoms.ts
index c6c33b3..318c6c8 100644
--- a/Frontend/erp-system/lib/api/uoms.ts
+++ b/Frontend/erp-system/lib/api/uoms.ts
@@ -1,27 +1,10 @@
 // One typed client method per UOM endpoint (docs/11-BACKEND-PHASE1.md §2.2, FR-MD-02).
 // `list` also backs the GRN/PO line UOM picker built in earlier sessions.
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so these screens
-// can be reviewed without a running backend. Restore the commented block and
-// delete the mock block once Backend/PROGRESS.md §1 (Master Data) exists.
+// In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { CreateUomRequest, Uom } from "@/types/master-data"
 import { allocateUomId, mockDelay, mockUoms } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest } from "@/lib/api-client"
-//
-// export const uomsApi = {
-//   list() {
-//     return apiRequest<PagedResponse<Uom>>("/uoms")
-//   },
-//   create(request: CreateUomRequest) {
-//     return apiRequest<Uom>("/uoms", { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export const uomsApi = {
   list(): Promise<PagedResponse<Uom>> {
     return mockDelay({
diff --git a/Frontend/erp-system/lib/api/vendors.ts b/Frontend/erp-system/lib/api/vendors.ts
index 360c20e..6f06743 100644
--- a/Frontend/erp-system/lib/api/vendors.ts
+++ b/Frontend/erp-system/lib/api/vendors.ts
@@ -1,14 +1,8 @@
 // One typed client method per vendor (supplier) endpoint (docs/11-BACKEND-PHASE1.md
-// §2.4, FR-MD-06). "GET/PUT/PATCH follow the Item pattern" per the doc — ETag/If-Match
-// on update, PATCH status for deactivate (masters are deactivated, not hard-deleted,
-// FR-MD-08).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so these screens can
-// be reviewed without a running backend. Restore the commented block and delete
-// the mock block once Backend/PROGRESS.md §1 (Master Data) exists.
-import { ApiResult } from "@/lib/api-client"
-import { EntityStatus, PagedResponse } from "@/types/common"
+// §2.4, FR-MD-06). ETag/If-Match on update, PATCH status for deactivate (masters
+// are deactivated, not hard-deleted, FR-MD-08). In-memory sample data
+// (lib/api/mock-data.ts) — no backend API calls.
+import { ApiResult, EntityStatus, PagedResponse } from "@/types/common"
 import { Vendor } from "@/types/master-data"
 import {
   allocateVendorId,
@@ -19,45 +13,6 @@ import {
   mockVendors,
 } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest, apiRequestWithETag, buildQuery } from "@/lib/api-client"
-//
-// export interface ListVendorsParams {
-//   page?: number
-//   pageSize?: number
-//   q?: string
-//   status?: EntityStatus
-// }
-//
-// export interface CreateVendorRequest {
-//   code: string
-//   name: string
-//   terms?: string | null
-//   taxReg?: string | null
-//   currency: string
-// }
-//
-// export type UpdateVendorRequest = CreateVendorRequest
-//
-// export const vendorsApi = {
-//   list(params: ListVendorsParams = {}) {
-//     return apiRequest<PagedResponse<Vendor>>(`/vendors${buildQuery(params)}`)
-//   },
-//   get(vendorId: number) {
-//     return apiRequestWithETag<Vendor>(`/vendors/${vendorId}`)
-//   },
-//   create(request: CreateVendorRequest) {
-//     return apiRequestWithETag<Vendor>("/vendors", { method: "POST", body: request })
-//   },
-//   update(vendorId: number, request: UpdateVendorRequest, ifMatch: string) {
-//     return apiRequestWithETag<Vendor>(`/vendors/${vendorId}`, { method: "PUT", body: request, ifMatch })
-//   },
-//   updateStatus(vendorId: number, status: EntityStatus) {
-//     return apiRequest<void>(`/vendors/${vendorId}/status`, { method: "PATCH", body: { status } })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface ListVendorsParams {
   page?: number
   pageSize?: number
diff --git a/Frontend/erp-system/lib/api/warehouses.ts b/Frontend/erp-system/lib/api/warehouses.ts
index 8f130ec..546acd2 100644
--- a/Frontend/erp-system/lib/api/warehouses.ts
+++ b/Frontend/erp-system/lib/api/warehouses.ts
@@ -1,47 +1,9 @@
 // One typed client method per warehouse/bin endpoint (docs/11-BACKEND-PHASE1.md §2.5,
-// FR-MD-07/FR-WH-01).
-//
-// UI-ONLY MODE: the real fetch-based implementation is commented out below and
-// replaced with in-memory sample data (lib/api/mock-data.ts) so the GRN/Stock/
-// Warehouse screens can be reviewed without a running backend. Restore the
-// commented block and delete the mock block once Backend/PROGRESS.md §1
-// (Master Data) exists.
+// FR-MD-07/FR-WH-01). In-memory sample data (lib/api/mock-data.ts) — no backend API calls.
 import { PagedResponse } from "@/types/common"
 import { Bin, Warehouse } from "@/types/master-data"
 import { allocateBinId, allocateWarehouseId, mockBins, mockDelay, mockWarehouses } from "@/lib/api/mock-data"
 
-// --- Real implementation (restore when the backend exists) --------------------
-// import { apiRequest } from "@/lib/api-client"
-//
-// export interface CreateWarehouseRequest {
-//   code: string
-//   name: string
-// }
-//
-// export interface CreateBinRequest {
-//   code: string
-//   binType?: string | null
-// }
-//
-// export const warehousesApi = {
-//   list() {
-//     return apiRequest<PagedResponse<Warehouse>>("/warehouses")
-//   },
-//
-//   create(request: CreateWarehouseRequest) {
-//     return apiRequest<Warehouse>("/warehouses", { method: "POST", body: request })
-//   },
-//
-//   listBins(warehouseId: number) {
-//     return apiRequest<PagedResponse<Bin>>(`/warehouses/${warehouseId}/bins`)
-//   },
-//
-//   createBin(warehouseId: number, request: CreateBinRequest) {
-//     return apiRequest<Bin>(`/warehouses/${warehouseId}/bins`, { method: "POST", body: request })
-//   },
-// }
-
-// --- Mock implementation (UI-only review) --------------------------------------
 export interface CreateWarehouseRequest {
   code: string
   name: string
diff --git a/Frontend/erp-system/lib/auth-token.ts b/Frontend/erp-system/lib/auth-token.ts
deleted file mode 100644
index 56a9b3c..0000000
--- a/Frontend/erp-system/lib/auth-token.ts
+++ /dev/null
@@ -1,16 +0,0 @@
-// Bearer-token storage for the ERPCore API client (docs/20-FRONTEND.md §1).
-// Login (POST /auth/login) is not wired yet — reads simply return null until it is,
-// and the API client omits the Authorization header in that case.
-
-const STORAGE_KEY = "erpcore.accessToken"
-
-export function getAccessToken(): string | null {
-  if (typeof window === "undefined") return null
-  return window.localStorage.getItem(STORAGE_KEY)
-}
-
-export function setAccessToken(token: string | null) {
-  if (typeof window === "undefined") return
-  if (token) window.localStorage.setItem(STORAGE_KEY, token)
-  else window.localStorage.removeItem(STORAGE_KEY)
-}
diff --git a/Frontend/erp-system/lib/error-map.ts b/Frontend/erp-system/lib/error-map.ts
index 87a4528..4e72ac2 100644
--- a/Frontend/erp-system/lib/error-map.ts
+++ b/Frontend/erp-system/lib/error-map.ts
@@ -1,7 +1,12 @@
 // code -> user-facing message (docs/20-FRONTEND.md §3.2: "Keep a code -> message
 // map in lib/ so messages are consistent"). Falls back to the ProblemDetails
 // title/detail from the server when a code isn't in the map.
-import { ApiError } from "@/lib/api-client"
+
+interface ApiErrorLike {
+  code?: string
+  detail?: string
+  errors?: Record<string, string[]>
+}
 
 const CODE_MESSAGES: Record<string, string> = {
   OVER_RECEIPT_TOLERANCE: "This quantity exceeds the purchase order's open quantity beyond the allowed tolerance.",
@@ -21,21 +26,21 @@ const CODE_MESSAGES: Record<string, string> = {
 }
 
 export function errorMessage(error: unknown): string {
-  if (error instanceof ApiError) {
-    if (error.code && CODE_MESSAGES[error.code]) return CODE_MESSAGES[error.code]
-    return error.detail || error.message || "Something went wrong."
+  if (error && typeof error === "object") {
+    const e = error as ApiErrorLike
+    if (e.code && CODE_MESSAGES[e.code]) return CODE_MESSAGES[e.code]
+    if (e.detail) return e.detail
   }
   if (error instanceof Error) return error.message
   return "Something went wrong."
 }
 
 export function fieldErrors(error: unknown): Record<string, string> | null {
-  if (error instanceof ApiError && error.errors) {
-    const out: Record<string, string> = {}
-    for (const [field, messages] of Object.entries(error.errors)) {
-      out[field] = messages[0]
-    }
-    return out
+  const errors = error && typeof error === "object" ? (error as ApiErrorLike).errors : undefined
+  if (!errors) return null
+  const out: Record<string, string> = {}
+  for (const [field, messages] of Object.entries(errors)) {
+    out[field] = messages[0]
   }
-  return null
+  return out
 }
diff --git a/Frontend/erp-system/types/common.ts b/Frontend/erp-system/types/common.ts
index 9c614bd..52c4f6b 100644
--- a/Frontend/erp-system/types/common.ts
+++ b/Frontend/erp-system/types/common.ts
@@ -12,7 +12,13 @@ export interface PagedResponse<T> {
   pagination: PaginationMeta
 }
 
-/** RFC 7807 ProblemDetails, normalized by lib/api-client.ts. */
+/** A resource plus its concurrency token (docs/11 §1.6 ETag/If-Match), e.g. `vendorsApi.get()`. */
+export interface ApiResult<T> {
+  data: T
+  etag: string | null
+}
+
+/** RFC 7807 ProblemDetails shape (docs/11-BACKEND-PHASE1.md §1.8). */
 export interface ProblemDetails {
   type?: string
   title: string