Build inventory frontend and stock management features

- Full inventory UI: product list with search/filter, product detail with
  tabs (details, units, suppliers, stock receipts, price history)
- Product filters: category, type (serialized/rental/repair), low stock,
  active/inactive — all server-side with URL-synced state
- Product-supplier junction: link products to multiple suppliers with
  preferred flag, joined supplier details in UI
- Stock receipts: record incoming stock with supplier, qty, cost per unit,
  invoice number; auto-increments qty_on_hand for non-serialized products
- Price history tab on product detail page
- categories/all endpoint to avoid pagination limit on dropdown fetches
- categoryId filter on product list endpoint
- Repair parts and additional inventory items in music store seed data
- isDualUseRepair corrected: instruments set to false, strings/parts true
- Product-supplier links and stock receipts in seed data
- Price history seed data simulating cost increases over past year
- 37 API tests covering categories, suppliers, products, units,
  product-suppliers, and stock receipts
- alert-dialog and checkbox UI components
- sync-and-deploy.sh script for rsync + remote deploy

packages/backend/src/services/product.service.ts

@@ -1,12 +1,15 @@
-import { eq, and, count, type Column } from 'drizzle-orm'
+import { eq, and, count, desc, lte, sql, type Column } from 'drizzle-orm'
 import type { PostgresJsDatabase } from 'drizzle-orm/postgres-js'
-import { products, inventoryUnits, priceHistory } from '../db/schema/inventory.js'
+import { products, inventoryUnits, priceHistory as priceHistoryTable, productSuppliers, suppliers, stockReceipts } from '../db/schema/inventory.js'
 import { ValidationError } from '../lib/errors.js'
 import type {
   ProductCreateInput,
   ProductUpdateInput,
   InventoryUnitCreateInput,
   InventoryUnitUpdateInput,
+  ProductSupplierCreateInput,
+  ProductSupplierUpdateInput,
+  StockReceiptCreateInput,
   PaginationInput,
 } from '@lunarfront/shared/schemas'
 import {
@@ -40,14 +43,39 @@ export const ProductService = {
     return product ?? null
   },
 
-  async list(db: PostgresJsDatabase<any>, params: PaginationInput) {
-    const baseWhere = eq(products.isActive, true)
+  async list(db: PostgresJsDatabase<any>, params: PaginationInput, filters?: {
+    categoryId?: string
+    isActive?: boolean
+    isSerialized?: boolean
+    isRental?: boolean
+    isDualUseRepair?: boolean
+    lowStock?: boolean
+  }) {
+    const conditions = [eq(products.isActive, filters?.isActive ?? true)]
 
-    const searchCondition = params.q
-      ? buildSearchCondition(params.q, [products.name, products.sku, products.upc, products.brand])
-      : undefined
+    if (params.q) {
+      conditions.push(buildSearchCondition(params.q, [products.name, products.sku, products.upc, products.brand])!)
+    }
+    if (filters?.categoryId) {
+      conditions.push(eq(products.categoryId, filters.categoryId))
+    }
+    if (filters?.isSerialized !== undefined) {
+      conditions.push(eq(products.isSerialized, filters.isSerialized))
+    }
+    if (filters?.isRental !== undefined) {
+      conditions.push(eq(products.isRental, filters.isRental))
+    }
+    if (filters?.isDualUseRepair !== undefined) {
+      conditions.push(eq(products.isDualUseRepair, filters.isDualUseRepair))
+    }
+    if (filters?.lowStock) {
+      // qty_on_hand <= qty_reorder_point (and reorder point is set) OR qty_on_hand = 0
+      conditions.push(
+        sql`(${products.qtyOnHand} = 0 OR (${products.qtyReorderPoint} IS NOT NULL AND ${products.qtyOnHand} <= ${products.qtyReorderPoint}))`
+      )
+    }
 
-    const where = searchCondition ? and(baseWhere, searchCondition) : baseWhere
+    const where = conditions.length === 1 ? conditions[0] : and(...conditions)
 
     const sortableColumns: Record<string, Column> = {
       name: products.name,
@@ -78,7 +106,7 @@ export const ProductService = {
     if (input.price !== undefined || input.minPrice !== undefined) {
       const existing = await this.getById(db, id)
       if (existing) {
-        await db.insert(priceHistory).values({
+        await db.insert(priceHistoryTable).values({
           productId: id,
           previousPrice: existing.price,
           newPrice: input.price?.toString() ?? existing.price ?? '0',
@@ -111,6 +139,14 @@ export const ProductService = {
       .returning()
     return product ?? null
   },
+
+  async listPriceHistory(db: PostgresJsDatabase<any>, productId: string) {
+    return db
+      .select()
+      .from(priceHistoryTable)
+      .where(eq(priceHistoryTable.productId, productId))
+      .orderBy(desc(priceHistoryTable.createdAt))
+  },
 }
 
 export const InventoryUnitService = {
@@ -200,3 +236,118 @@ export const InventoryUnitService = {
     return unit ?? null
   },
 }
+
+export const ProductSupplierService = {
+  async listByProduct(db: PostgresJsDatabase<any>, productId: string) {
+    return db
+      .select({
+        id: productSuppliers.id,
+        productId: productSuppliers.productId,
+        supplierId: productSuppliers.supplierId,
+        supplierSku: productSuppliers.supplierSku,
+        isPreferred: productSuppliers.isPreferred,
+        createdAt: productSuppliers.createdAt,
+        supplierName: suppliers.name,
+        supplierContactName: suppliers.contactName,
+        supplierEmail: suppliers.email,
+        supplierPhone: suppliers.phone,
+        supplierAccountNumber: suppliers.accountNumber,
+        supplierPaymentTerms: suppliers.paymentTerms,
+      })
+      .from(productSuppliers)
+      .innerJoin(suppliers, eq(productSuppliers.supplierId, suppliers.id))
+      .where(eq(productSuppliers.productId, productId))
+      .orderBy(desc(productSuppliers.isPreferred), suppliers.name)
+  },
+
+  async create(db: PostgresJsDatabase<any>, productId: string, input: ProductSupplierCreateInput) {
+    if (input.isPreferred) {
+      await db
+        .update(productSuppliers)
+        .set({ isPreferred: false })
+        .where(eq(productSuppliers.productId, productId))
+    }
+    const [row] = await db
+      .insert(productSuppliers)
+      .values({ productId, ...input })
+      .returning()
+    return row
+  },
+
+  async update(db: PostgresJsDatabase<any>, id: string, productId: string, input: ProductSupplierUpdateInput) {
+    if (input.isPreferred) {
+      await db
+        .update(productSuppliers)
+        .set({ isPreferred: false })
+        .where(eq(productSuppliers.productId, productId))
+    }
+    const [row] = await db
+      .update(productSuppliers)
+      .set(input)
+      .where(eq(productSuppliers.id, id))
+      .returning()
+    return row ?? null
+  },
+
+  async delete(db: PostgresJsDatabase<any>, id: string) {
+    const [row] = await db
+      .delete(productSuppliers)
+      .where(eq(productSuppliers.id, id))
+      .returning()
+    return row ?? null
+  },
+}
+
+export const StockReceiptService = {
+  async create(db: PostgresJsDatabase<any>, productId: string, input: StockReceiptCreateInput) {
+    const totalCost = (input.costPerUnit * input.qty).toFixed(2)
+
+    const [receipt] = await db
+      .insert(stockReceipts)
+      .values({
+        productId,
+        supplierId: input.supplierId,
+        inventoryUnitId: input.inventoryUnitId,
+        qty: input.qty,
+        costPerUnit: input.costPerUnit.toString(),
+        totalCost,
+        receivedDate: input.receivedDate,
+        invoiceNumber: input.invoiceNumber,
+        notes: input.notes,
+      })
+      .returning()
+
+    // For non-serialized products, increment qty_on_hand
+    const [product] = await db.select().from(products).where(eq(products.id, productId)).limit(1)
+    if (product && !product.isSerialized) {
+      await db
+        .update(products)
+        .set({ qtyOnHand: product.qtyOnHand + input.qty, updatedAt: new Date() })
+        .where(eq(products.id, productId))
+    }
+
+    return receipt
+  },
+
+  async listByProduct(db: PostgresJsDatabase<any>, productId: string) {
+    return db
+      .select({
+        id: stockReceipts.id,
+        productId: stockReceipts.productId,
+        supplierId: stockReceipts.supplierId,
+        inventoryUnitId: stockReceipts.inventoryUnitId,
+        qty: stockReceipts.qty,
+        costPerUnit: stockReceipts.costPerUnit,
+        totalCost: stockReceipts.totalCost,
+        receivedDate: stockReceipts.receivedDate,
+        invoiceNumber: stockReceipts.invoiceNumber,
+        notes: stockReceipts.notes,
+        createdAt: stockReceipts.createdAt,
+        supplierName: suppliers.name,
+      })
+      .from(stockReceipts)
+      .leftJoin(suppliers, eq(stockReceipts.supplierId, suppliers.id))
+      .where(eq(stockReceipts.productId, productId))
+      .orderBy(desc(stockReceipts.receivedDate), desc(stockReceipts.createdAt))
+  },
+}