diff --git a/.commandcode/taste/taste/taste.md b/.commandcode/taste/taste/taste.md
index c8e17be..209106b 100644
--- a/.commandcode/taste/taste/taste.md
+++ b/.commandcode/taste/taste/taste.md
@@ -95,6 +95,10 @@ er-ui/app/(drawer)/(tabs)/home/index.tsx, I want similar here") and expects the
 - For analysis documents, expects a consistent naming pattern following the established convention (`user_ui_dpsk.md` → `admin_ui_dpsk.md`, i.e., `{app}_dpsk.md` at the repo root) rather than an ad-hoc filename — "make another md file with same naming pattern"; the `_dpsk.md` suffix also applies to cross-cutting topic analyses (e.g., `repeat_types_dpsk.md` for the repeated-types scan). Confidence: 0.9
 - When commissioning a cross-cutting audit/analysis, expects the scan to span the entire monorepo in one pass — every app, the backend, AND the shared packages (e.g., "scan the entire @apps/user-ui/ @apps/admin-ui/ @apps/backend/ and also entire @packages/") — not just one app or one area. Confidence: 0.65
 - Values type-level hygiene alongside runtime structures: wants repeated type declarations across the monorepo hunted down and classified (identical duplicates, near-identical/unifiable shapes, same-name-different-shape collisions) and documented in a report before any refactor, rather than fixing types piecemeal. Confidence: 0.6
+
+- Requires the parallel DB-helper packages (db_helper_sqlite and db_helper_postgres) to not duplicate type definitions: they must share one canonical set of types and emit exactly the same data shape, since they represent the same business entities on different backends — stated directly: "they shouldn't duplicate types. They should emit exactly same type of data. They should share the types." Confidence: 0.9
+
+- When the two DB-helper implementations diverge at the data-model level (sqlite is SKU-based with skuIds; the dormant postgres collapsed the SKU tier into productIds), the live/canonical model wins: the sqlite/SKU model — which packages/shared already standardizes on — is the source of truth and the dormant postgres helper is to be aligned/migrated to it (up to and including schema-level changes so even row types match), not the reverse. Confidence: 0.75
 e changes. Confidence: 0.95
 er-ui/app/(drawer)/(tabs)/home/index.tsx, I want similar here") and expects the agent to mirror that pattern exactly, including details like item counts and container styling. Confidence: 0.9
 als) rather than introducing new brand palettes; approval of a redesign's layout/composition does not imply approval of color or theme changes. Confidence: 0.95
diff --git a/apps/backend/src/middleware/auth.middleware.ts b/apps/backend/src/middleware/auth.middleware.ts
index 71af065..9a0989d 100644
--- a/apps/backend/src/middleware/auth.middleware.ts
+++ b/apps/backend/src/middleware/auth.middleware.ts
@@ -4,18 +4,6 @@ import { getStaffUserById, isUserSuspended } from '@/src/dbService';
 import { ApiError } from '@/src/lib/api-error';
 import { getEncodedJwtSecret } from '@/src/lib/env-exporter';
 
-interface UserContext {
-  userId: number;
-  name?: string;
-  email?: string;
-  mobile?: string;
-}
-
-interface StaffContext {
-  id: number;
-  name: string;
-}
-
 export const authenticateUser = async (c: Context, next: Next) => {
   try {
     const authHeader = c.req.header('authorization');
diff --git a/change-log.txt b/change-log.txt
index f374d1c..b851b47 100644
--- a/change-log.txt
+++ b/change-log.txt
@@ -632,3 +632,63 @@ Verification:
 - grep across apps + packages: zero references to any removed legacy type name or the token-types module.
 - CreateCouponPayload intact; its only importers (admin-ui coupons/edit/[id].tsx + src/components/CouponForm.tsx) unchanged.
 - Pre-existing tsc error in coupons/edit/[id].tsx:92 (`skuIds` not in CreateCouponPayload) untouched and unrelated (predates this change; CreateCouponPayload body preserved byte-for-byte).
+
+[2026-09-03 20:03:29] DELETE unused types (no consumers repo-wide; scanner: scripts/dead-code/unused-types.js; ambient .d.ts declarations excluded by design).
+NOTE: date rollover — this entry and deletions performed 2026-09-03.
+
+=== apps/backend/src/middleware/auth.middleware.ts ===
+- removed interface UserContext (lines 7-12):
+    interface UserContext {
+      userId: number;
+      name?: string;
+      email?: string;
+      mobile?: string;
+    }
+- removed interface StaffContext (lines 14-17):
+    interface StaffContext {
+      id: number;
+      name: string;
+    }
+  (file types context vars via hono's ContextVariableMap augmentation in types/hono.d.ts — those ambient declarations KEPT, they are consumed by hono's type system, not by name)
+
+=== packages/shared/types/coupon.types.ts ===
+- removed interface ReservedCoupon (lines 21-25):
+    export interface ReservedCoupon extends Coupon {
+      secretCode: string;
+      redeemedUserId: number | null;
+      redeemedAt: Date | null;
+    }
+
+=== packages/shared/types/user.ts ===
+- removed interface UserAvailabilityEntry (lines 339-345) — transitively dead (only consumer was UserAvailabilityResponse):
+    export interface UserAvailabilityEntry {
+      id: number;
+      price: string;
+      marketPrice: string | null;
+      flashPrice: string | null;
+      isFlashAvailable: boolean;
+      isOutOfStock: boolean;
+      isSuspended: boolean;
+    }
+- removed interface UserAvailabilityResponse (lines 347-350):
+    export interface UserAvailabilityResponse {
+      availability: UserAvailabilityEntry[];
+      count: number;
+    }
+
+=== packages/ui/src/components/use-pick-image.tsx ===
+- removed interface BaseProps (lines 5-8):
+    interface BaseProps {
+      label?: string;
+      multiple: boolean;
+    }
+- removed interface ImageInfo (lines 22-36) — 15-field expo ImagePicker asset mirror, never referenced (picker assets are spread as any)
+  (live hook + its Props type kept; file has 7 consumers)
+
+[2026-09-03 20:06:30] COMPLETED unused-type deletion: 7 types removed across 4 files.
+- auth.middleware.ts: UserContext, StaffContext (kept hono.d.ts ContextVariableMap — ambient module augmentation, consumed by hono's type system)
+- shared/coupon.types.ts: ReservedCoupon
+- shared/user.ts: UserAvailabilityResponse + UserAvailabilityEntry (transitively dead — only consumer was the removed response type)
+- ui/use-pick-image.tsx: BaseProps, ImageInfo
+Verification: zero leftover references repo-wide; tsc baselines unchanged — backend 11, packages/ui 924, user-ui 106, admin-ui 122 (all pre-existing).
+Scanner limitation noted: same-name declarations across files (e.g. Props, Order) can mask per-copy deadness via word-boundary matching; those require import-graph resolution and were not touched.
diff --git a/packages/shared/types/coupon.types.ts b/packages/shared/types/coupon.types.ts
index 4f4c0a8..c89afe2 100644
--- a/packages/shared/types/coupon.types.ts
+++ b/packages/shared/types/coupon.types.ts
@@ -21,12 +21,6 @@ export interface Coupon {
   createdBy: number;
 }
 
-export interface ReservedCoupon extends Coupon {
-  secretCode: string;
-  redeemedUserId: number | null;
-  redeemedAt: Date | null;
-}
-
 export interface CouponValidationResult {
   valid: boolean;
   message?: string;
diff --git a/packages/shared/types/user.ts b/packages/shared/types/user.ts
index e98bd3f..6eed4c5 100644
--- a/packages/shared/types/user.ts
+++ b/packages/shared/types/user.ts
@@ -336,21 +336,6 @@ export interface UserSlotAvailability {
   isOutOfStock: boolean;
 }
 
-export interface UserAvailabilityEntry {
-  id: number;
-  price: string;
-  marketPrice: string | null;
-  flashPrice: string | null;
-  isFlashAvailable: boolean;
-  isOutOfStock: boolean;
-  isSuspended: boolean;
-}
-
-export interface UserAvailabilityResponse {
-  availability: UserAvailabilityEntry[];
-  count: number;
-}
-
 export interface UserDeliverySlot {
   id: number;
   deliveryTime: Date;
diff --git a/packages/ui/src/components/use-pick-image.tsx b/packages/ui/src/components/use-pick-image.tsx
index 9982d6c..2ef52db 100644
--- a/packages/ui/src/components/use-pick-image.tsx
+++ b/packages/ui/src/components/use-pick-image.tsx
@@ -2,11 +2,6 @@ import React from "react";
 import * as DocumentPicker from "expo-document-picker";
 import * as ImagePicker from "expo-image-picker";
 
-interface BaseProps {
-  label?: string;
-  multiple: boolean;
-}
-
 // interface Props {
 //     setFile: (file: DocumentPicker.DocumentPickerAsset | null) => void;
 //     label?: string;
@@ -19,22 +14,6 @@ type Props = {
   multiple: boolean;
 };
 
-interface ImageInfo {
-  assetId?: string | null;
-  base64?: string | null;
-  duration?: number | null;
-  exif?: Record<string, any> | null;
-  fileName?: string | null;
-  fileSize?: number;
-  height?: number;
-  mimeType?: string | null;
-  name?: string | null;
-  rotation?: number | null;
-  type?: string;
-  uri: string;
-  width?: number;
-}
-
 function usePickImage({ setFile, multiple = false }: Props) {
   // const { setFile } = props;
   const handlePickFile = async () => {