Merge pull request 'feat: implement inventory CRUD UI components (#18 #19 #20 #21)' (#46) from feature/issue-18-21-inventory-ui into develop

Week 2 core inventory management:

**Composables:**
- useInventory: Full CRUD operations for inventory items
- useUnits: Unit fetching and conversion helpers
- useTags: Tag fetching and category filtering

**Components:**
- InventoryList (#18): Grid view with loading/empty/error states
- InventoryCard: Item card with image, quantity controls, tags, expiry
- AddItemForm (#19): Form with tag picker, unit selector, validation
- EditItemModal (#20): Modal form for editing existing items
- Delete functionality (#21): Confirm dialog + cascade tag cleanup

**Features:**
- Quantity quick-actions (+/- buttons on cards)
- Auto-delete when quantity reaches zero
- Expiry date tracking with color-coded warnings
- Tag selection by category in add form
- Responsive grid layout (1-4 columns)
- Product image display from barcode cache
- Form validation and loading states

Closes #18, #19, #20, #21

app/components/inventory/AddItemForm.vue

@@ -0,0 +1,257 @@
+<template>
+  <UCard>
+    <template #header>
+      <div class="flex items-center justify-between">
+        <h3 class="text-lg font-semibold">Add New Item</h3>
+        <UButton 
+          icon="i-heroicons-x-mark" 
+          color="gray" 
+          variant="ghost"
+          @click="$emit('close')"
+        />
+      </div>
+    </template>
+
+    <form @submit.prevent="handleSubmit" class="space-y-4">
+      <!-- Item Name -->
+      <UFormGroup label="Item Name" required>
+        <UInput 
+          v-model="form.name"
+          placeholder="e.g. Whole Milk, Pasta, Tomatoes"
+          size="lg"
+          autofocus
+        />
+      </UFormGroup>
+
+      <!-- Quantity & Unit -->
+      <div class="grid grid-cols-2 gap-3">
+        <UFormGroup label="Quantity" required>
+          <UInput 
+            v-model.number="form.quantity"
+            type="number"
+            min="0.01"
+            step="0.01"
+            placeholder="1"
+            size="lg"
+          />
+        </UFormGroup>
+
+        <UFormGroup label="Unit" required>
+          <USelect 
+            v-model="form.unit_id"
+            :options="unitOptions"
+            option-attribute="label"
+            value-attribute="value"
+            placeholder="Select unit"
+            size="lg"
+          />
+        </UFormGroup>
+      </div>
+
+      <!-- Expiry Date -->
+      <UFormGroup label="Expiry Date" hint="Optional">
+        <UInput 
+          v-model="form.expiry_date"
+          type="date"
+          size="lg"
+        />
+      </UFormGroup>
+
+      <!-- Notes -->
+      <UFormGroup label="Notes" hint="Optional">
+        <UTextarea
+          v-model="form.notes"
+          placeholder="Any additional notes..."
+          :rows="2"
+        />
+      </UFormGroup>
+
+      <!-- Tags -->
+      <UFormGroup label="Tags" hint="Optional">
+        <div class="space-y-2">
+          <!-- Selected Tags -->
+          <div v-if="selectedTags.length > 0" class="flex flex-wrap gap-1 mb-2">
+            <UBadge 
+              v-for="tag in selectedTags" 
+              :key="tag.id"
+              :style="{ backgroundColor: tag.color }"
+              class="text-white cursor-pointer"
+              @click="removeTag(tag.id)"
+            >
+              {{ tag.icon }} {{ tag.name }} ✕
+            </UBadge>
+          </div>
+
+          <!-- Tag Selection by Category -->
+          <div v-for="category in tagCategories" :key="category.name" class="space-y-1">
+            <p class="text-xs font-medium text-gray-500 uppercase">{{ category.name }}</p>
+            <div class="flex flex-wrap gap-1">
+              <UButton
+                v-for="tag in category.tags"
+                :key="tag.id"
+                size="xs"
+                :color="isTagSelected(tag.id) ? 'primary' : 'gray'"
+                :variant="isTagSelected(tag.id) ? 'solid' : 'outline'"
+                @click="toggleTag(tag)"
+              >
+                {{ tag.icon }} {{ tag.name }}
+              </UButton>
+            </div>
+          </div>
+        </div>
+      </UFormGroup>
+
+      <!-- Submit -->
+      <div class="flex gap-2 pt-2">
+        <UButton 
+          type="submit"
+          color="primary"
+          size="lg"
+          class="flex-1"
+          :loading="submitting"
+          :disabled="!isValid"
+        >
+          Add Item
+        </UButton>
+        <UButton 
+          color="gray"
+          size="lg"
+          variant="soft"
+          @click="$emit('close')"
+        >
+          Cancel
+        </UButton>
+      </div>
+    </form>
+  </UCard>
+</template>
+
+<script setup lang="ts">
+const { addInventoryItem, addItemTags } = useInventory()
+const { getUnits } = useUnits()
+const { getTags } = useTags()
+
+const emit = defineEmits<{
+  close: []
+  added: [item: any]
+}>()
+
+// Form state
+const form = reactive({
+  name: '',
+  quantity: 1,
+  unit_id: '',
+  expiry_date: '',
+  notes: ''
+})
+
+const submitting = ref(false)
+const selectedTags = ref<any[]>([])
+
+// Load units and tags
+const units = ref<any[]>([])
+const tags = ref<any[]>([])
+
+onMounted(async () => {
+  const [unitsResult, tagsResult] = await Promise.all([
+    getUnits(),
+    getTags()
+  ])
+
+  units.value = unitsResult.data || []
+  tags.value = tagsResult.data || []
+
+  // Set default unit (Piece)
+  const defaultUnit = units.value.find(u => u.abbreviation === 'pc')
+  if (defaultUnit) {
+    form.unit_id = defaultUnit.id
+  }
+})
+
+// Unit options for select
+const unitOptions = computed(() => {
+  const grouped: Record<string, any[]> = {}
+  
+  for (const unit of units.value) {
+    const type = unit.unit_type
+    if (!grouped[type]) grouped[type] = []
+    grouped[type].push({
+      label: `${unit.name} (${unit.abbreviation})`,
+      value: unit.id
+    })
+  }
+
+  return Object.entries(grouped).flatMap(([type, options]) => [
+    { label: `— ${type.charAt(0).toUpperCase() + type.slice(1)} —`, value: '', disabled: true },
+    ...options
+  ])
+})
+
+// Tag categories for display
+const tagCategories = computed(() => {
+  const categories: Record<string, any[]> = {}
+  
+  for (const tag of tags.value) {
+    const cat = tag.category
+    if (!categories[cat]) categories[cat] = []
+    categories[cat].push(tag)
+  }
+
+  return Object.entries(categories).map(([name, tags]) => ({
+    name,
+    tags
+  }))
+})
+
+// Tag selection helpers
+const isTagSelected = (tagId: string) => {
+  return selectedTags.value.some(t => t.id === tagId)
+}
+
+const toggleTag = (tag: any) => {
+  if (isTagSelected(tag.id)) {
+    removeTag(tag.id)
+  } else {
+    selectedTags.value.push(tag)
+  }
+}
+
+const removeTag = (tagId: string) => {
+  selectedTags.value = selectedTags.value.filter(t => t.id !== tagId)
+}
+
+// Validation
+const isValid = computed(() => {
+  return form.name.trim().length > 0 && form.quantity > 0 && form.unit_id
+})
+
+// Submit
+const handleSubmit = async () => {
+  if (!isValid.value) return
+
+  submitting.value = true
+
+  const { data, error } = await addInventoryItem({
+    name: form.name.trim(),
+    quantity: form.quantity,
+    unit_id: form.unit_id,
+    expiry_date: form.expiry_date || null,
+    notes: form.notes.trim() || null
+  })
+
+  if (error) {
+    alert('Failed to add item: ' + error.message)
+    submitting.value = false
+    return
+  }
+
+  // Add tags if any selected
+  if (data && selectedTags.value.length > 0) {
+    const tagIds = selectedTags.value.map(t => t.id)
+    await addItemTags(data.id, tagIds)
+  }
+
+  emit('added', data)
+  submitting.value = false
+}
+</script>

app/components/inventory/EditItemModal.vue

@@ -0,0 +1,184 @@
+<template>
+  <UModal v-model="isOpen">
+    <UCard>
+      <template #header>
+        <div class="flex items-center justify-between">
+          <h3 class="text-lg font-semibold">Edit Item</h3>
+          <UButton 
+            icon="i-heroicons-x-mark" 
+            color="gray" 
+            variant="ghost"
+            @click="close"
+          />
+        </div>
+      </template>
+
+      <form @submit.prevent="handleSubmit" class="space-y-4">
+        <!-- Item Name -->
+        <UFormGroup label="Item Name" required>
+          <UInput 
+            v-model="form.name"
+            placeholder="Item name"
+            size="lg"
+          />
+        </UFormGroup>
+
+        <!-- Quantity & Unit -->
+        <div class="grid grid-cols-2 gap-3">
+          <UFormGroup label="Quantity" required>
+            <UInput 
+              v-model.number="form.quantity"
+              type="number"
+              min="0.01"
+              step="0.01"
+              size="lg"
+            />
+          </UFormGroup>
+
+          <UFormGroup label="Unit" required>
+            <USelect 
+              v-model="form.unit_id"
+              :options="unitOptions"
+              option-attribute="label"
+              value-attribute="value"
+              size="lg"
+            />
+          </UFormGroup>
+        </div>
+
+        <!-- Expiry Date -->
+        <UFormGroup label="Expiry Date" hint="Optional">
+          <UInput 
+            v-model="form.expiry_date"
+            type="date"
+            size="lg"
+          />
+        </UFormGroup>
+
+        <!-- Notes -->
+        <UFormGroup label="Notes" hint="Optional">
+          <UTextarea
+            v-model="form.notes"
+            placeholder="Any additional notes..."
+            :rows="2"
+          />
+        </UFormGroup>
+
+        <!-- Submit -->
+        <div class="flex gap-2 pt-2">
+          <UButton 
+            type="submit"
+            color="primary"
+            size="lg"
+            class="flex-1"
+            :loading="submitting"
+            :disabled="!isValid"
+          >
+            Save Changes
+          </UButton>
+          <UButton 
+            color="gray"
+            size="lg"
+            variant="soft"
+            @click="close"
+          >
+            Cancel
+          </UButton>
+        </div>
+      </form>
+    </UCard>
+  </UModal>
+</template>
+
+<script setup lang="ts">
+const { updateInventoryItem } = useInventory()
+const { getUnits } = useUnits()
+
+const props = defineProps<{
+  item: any | null
+}>()
+
+const emit = defineEmits<{
+  close: []
+  updated: [item: any]
+}>()
+
+const isOpen = ref(false)
+const submitting = ref(false)
+const units = ref<any[]>([])
+
+const form = reactive({
+  name: '',
+  quantity: 1,
+  unit_id: '',
+  expiry_date: '',
+  notes: ''
+})
+
+// Load units
+onMounted(async () => {
+  const { data } = await getUnits()
+  units.value = data || []
+})
+
+// Unit options for select
+const unitOptions = computed(() => {
+  return units.value.map(unit => ({
+    label: `${unit.name} (${unit.abbreviation})`,
+    value: unit.id
+  }))
+})
+
+// Watch for item changes (open modal)
+watch(() => props.item, (newItem) => {
+  if (newItem) {
+    form.name = newItem.name
+    form.quantity = Number(newItem.quantity)
+    form.unit_id = newItem.unit_id
+    form.expiry_date = newItem.expiry_date || ''
+    form.notes = newItem.notes || ''
+    isOpen.value = true
+  }
+}, { immediate: true })
+
+// Watch modal close
+watch(isOpen, (val) => {
+  if (!val) {
+    emit('close')
+  }
+})
+
+// Validation
+const isValid = computed(() => {
+  return form.name.trim().length > 0 && form.quantity > 0 && form.unit_id
+})
+
+const close = () => {
+  isOpen.value = false
+}
+
+// Submit
+const handleSubmit = async () => {
+  if (!isValid.value || !props.item) return
+
+  submitting.value = true
+
+  const { data, error } = await updateInventoryItem(props.item.id, {
+    name: form.name.trim(),
+    quantity: form.quantity,
+    unit_id: form.unit_id,
+    expiry_date: form.expiry_date || null,
+    notes: form.notes.trim() || null
+  })
+
+  if (error) {
+    alert('Failed to update item: ' + error.message)
+    submitting.value = false
+    return
+  }
+
+  emit('updated', data)
+  submitting.value = false
+  close()
+}
+</script>

app/components/inventory/InventoryCard.vue

@@ -0,0 +1,151 @@
+<template>
+  <UCard class="hover:shadow-lg transition-shadow">
+    <!-- Item Image -->
+    <div class="aspect-square bg-gray-100 rounded-lg mb-3 overflow-hidden">
+      <img 
+        v-if="item.product?.image_url" 
+        :src="item.product.image_url" 
+        :alt="item.name"
+        class="w-full h-full object-cover"
+      />
+      <div v-else class="w-full h-full flex items-center justify-center">
+        <UIcon name="i-heroicons-cube" class="w-16 h-16 text-gray-300" />
+      </div>
+    </div>
+
+    <!-- Item Info -->
+    <div class="space-y-2">
+      <div>
+        <h3 class="font-semibold text-gray-900 truncate">{{ item.name }}</h3>
+        <p v-if="item.product?.brand" class="text-sm text-gray-600 truncate">
+          {{ item.product.brand }}
+        </p>
+      </div>
+
+      <!-- Quantity -->
+      <div class="flex items-center justify-between">
+        <span class="text-lg font-medium text-gray-900">
+          {{ item.quantity }} {{ item.unit?.abbreviation }}
+        </span>
+
+        <!-- Quick Actions -->
+        <div class="flex gap-1">
+          <UButton 
+            icon="i-heroicons-minus"
+            size="xs"
+            color="gray"
+            variant="ghost"
+            @click="$emit('update-quantity', item.id, -1)"
+            :disabled="item.quantity <= 1"
+          />
+          <UButton 
+            icon="i-heroicons-plus"
+            size="xs"
+            color="gray"
+            variant="ghost"
+            @click="$emit('update-quantity', item.id, 1)"
+          />
+        </div>
+      </div>
+
+      <!-- Tags -->
+      <div v-if="item.tags && item.tags.length > 0" class="flex flex-wrap gap-1">
+        <UBadge 
+          v-for="tagItem in item.tags.slice(0, 3)" 
+          :key="tagItem.tag.id"
+          :style="{ backgroundColor: tagItem.tag.color }"
+          size="xs"
+          class="text-white"
+        >
+          {{ tagItem.tag.icon }} {{ tagItem.tag.name }}
+        </UBadge>
+        <UBadge v-if="item.tags.length > 3" size="xs" color="gray">
+          +{{ item.tags.length - 3 }}
+        </UBadge>
+      </div>
+
+      <!-- Expiry Warning -->
+      <div v-if="daysUntilExpiry !== null" class="text-xs">
+        <UBadge 
+          :color="expiryColor"
+          variant="soft"
+          class="w-full justify-center"
+        >
+          <UIcon :name="expiryIcon" class="mr-1" />
+          {{ expiryText }}
+        </UBadge>
+      </div>
+    </div>
+
+    <!-- Action Buttons -->
+    <template #footer>
+      <div class="flex gap-2">
+        <UButton 
+          icon="i-heroicons-pencil"
+          size="sm"
+          color="gray"
+          variant="soft"
+          class="flex-1"
+          @click="$emit('edit', item)"
+        >
+          Edit
+        </UButton>
+        <UButton 
+          icon="i-heroicons-trash"
+          size="sm"
+          color="red"
+          variant="soft"
+          @click="$emit('delete', item.id)"
+        >
+          Delete
+        </UButton>
+      </div>
+    </template>
+  </UCard>
+</template>
+
+<script setup lang="ts">
+const props = defineProps<{
+  item: any
+}>()
+
+defineEmits<{
+  edit: [item: any]
+  delete: [id: string]
+  'update-quantity': [id: string, change: number]
+}>()
+
+// Calculate days until expiry
+const daysUntilExpiry = computed(() => {
+  if (!props.item.expiry_date) return null
+  
+  const today = new Date()
+  const expiry = new Date(props.item.expiry_date)
+  const diff = Math.ceil((expiry.getTime() - today.getTime()) / (1000 * 60 * 60 * 24))
+  
+  return diff
+})
+
+// Expiry badge styling
+const expiryColor = computed(() => {
+  if (daysUntilExpiry.value === null) return 'gray'
+  if (daysUntilExpiry.value < 0) return 'red'
+  if (daysUntilExpiry.value <= 3) return 'orange'
+  if (daysUntilExpiry.value <= 7) return 'yellow'
+  return 'green'
+})
+
+const expiryIcon = computed(() => {
+  if (daysUntilExpiry.value === null) return 'i-heroicons-calendar'
+  if (daysUntilExpiry.value < 0) return 'i-heroicons-exclamation-triangle'
+  return 'i-heroicons-clock'
+})
+
+const expiryText = computed(() => {
+  if (daysUntilExpiry.value === null) return 'No expiry'
+  if (daysUntilExpiry.value < 0) return `Expired ${Math.abs(daysUntilExpiry.value)} days ago`
+  if (daysUntilExpiry.value === 0) return 'Expires today'
+  if (daysUntilExpiry.value === 1) return 'Expires tomorrow'
+  return `Expires in ${daysUntilExpiry.value} days`
+})
+</script>

app/components/inventory/InventoryList.vue

@@ -0,0 +1,131 @@
+<template>
+  <div class="space-y-4">
+    <!-- Loading State -->
+    <div v-if="loading" class="text-center py-12">
+      <UIcon name="i-heroicons-arrow-path" class="w-8 h-8 text-gray-400 animate-spin mx-auto mb-2" />
+      <p class="text-gray-600">Loading inventory...</p>
+    </div>
+
+    <!-- Error State -->
+    <div v-else-if="error" class="text-center py-12">
+      <UIcon name="i-heroicons-exclamation-triangle" class="w-12 h-12 text-red-500 mx-auto mb-4" />
+      <p class="text-red-600 mb-4">{{ error }}</p>
+      <UButton @click="loadInventory" color="gray">Retry</UButton>
+    </div>
+
+    <!-- Empty State -->
+    <div v-else-if="!items || items.length === 0" class="text-center py-12">
+      <UIcon name="i-heroicons-inbox" class="w-16 h-16 text-gray-400 mx-auto mb-4" />
+      <h3 class="text-lg font-semibold text-gray-900 mb-2">
+        No items yet
+      </h3>
+      <p class="text-gray-600 mb-6">
+        Start by scanning a barcode or adding an item manually.
+      </p>
+      <div class="flex gap-2 justify-center">
+        <UButton 
+          to="/scan" 
+          color="primary"
+          icon="i-heroicons-qr-code"
+        >
+          Scan First Item
+        </UButton>
+        <UButton 
+          @click="$emit('add-item')"
+          color="white"
+          icon="i-heroicons-plus"
+        >
+          Add Manually
+        </UButton>
+      </div>
+    </div>
+
+    <!-- Inventory Grid -->
+    <div v-else class="grid gap-4 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4">
+      <InventoryCard
+        v-for="item in items"
+        :key="item.id"
+        :item="item"
+        @edit="$emit('edit-item', item)"
+        @delete="handleDelete(item.id)"
+        @update-quantity="handleQuantityUpdate"
+      />
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+const { getInventory, deleteInventoryItem, updateQuantity } = useInventory()
+
+const props = defineProps<{
+  refresh?: boolean
+}>()
+
+const emit = defineEmits<{
+  'add-item': []
+  'edit-item': [item: any]
+}>()
+
+const items = ref<any[]>([])
+const loading = ref(true)
+const error = ref<string | null>(null)
+
+const loadInventory = async () => {
+  loading.value = true
+  error.value = null
+
+  const { data, error: fetchError } = await getInventory()
+
+  if (fetchError) {
+    error.value = 'Failed to load inventory. Please try again.'
+    loading.value = false
+    return
+  }
+
+  items.value = data || []
+  loading.value = false
+}
+
+const handleDelete = async (id: string) => {
+  if (!confirm('Are you sure you want to delete this item?')) {
+    return
+  }
+
+  const { error: deleteError } = await deleteInventoryItem(id)
+
+  if (deleteError) {
+    alert('Failed to delete item')
+    return
+  }
+
+  // Remove from local list
+  items.value = items.value.filter(item => item.id !== id)
+}
+
+const handleQuantityUpdate = async (id: string, change: number) => {
+  const result = await updateQuantity(id, change)
+
+  if (result.error) {
+    alert('Failed to update quantity')
+    return
+  }
+
+  // Reload inventory after update
+  await loadInventory()
+}
+
+// Load on mount
+onMounted(loadInventory)
+
+// Watch for refresh prop
+watch(() => props.refresh, (newVal) => {
+  if (newVal) {
+    loadInventory()
+  }
+})
+
+// Expose reload method
+defineExpose({
+  reload: loadInventory
+})
+</script>

app/composables/useInventory.ts

@@ -0,0 +1,201 @@
+import type { Database } from '~/types/database.types'
+
+type InventoryItem = Database['public']['Tables']['inventory_items']['Row']
+type InventoryItemInsert = Database['public']['Tables']['inventory_items']['Insert']
+type InventoryItemUpdate = Database['public']['Tables']['inventory_items']['Update']
+
+export const useInventory = () => {
+  const supabase = useSupabase()
+  const { user } = useSupabaseAuth()
+
+  /**
+   * Get all inventory items with denormalized data
+   */
+  const getInventory = async () => {
+    const { data, error } = await supabase
+      .from('inventory_items')
+      .select(`
+        *,
+        product:products(*),
+        unit:units(*),
+        tags:item_tags(tag:tags(*))
+      `)
+      .order('created_at', { ascending: false })
+
+    if (error) {
+      console.error('Error fetching inventory:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Get single inventory item by ID
+   */
+  const getInventoryItem = async (id: string) => {
+    const { data, error } = await supabase
+      .from('inventory_items')
+      .select(`
+        *,
+        product:products(*),
+        unit:units(*),
+        tags:item_tags(tag:tags(*))
+      `)
+      .eq('id', id)
+      .single()
+
+    if (error) {
+      console.error('Error fetching item:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Add new inventory item
+   */
+  const addInventoryItem = async (item: Omit<InventoryItemInsert, 'added_by'>) => {
+    if (!user.value) {
+      return { data: null, error: { message: 'User not authenticated' } }
+    }
+
+    const { data, error } = await supabase
+      .from('inventory_items')
+      .insert({
+        ...item,
+        added_by: user.value.id
+      })
+      .select(`
+        *,
+        product:products(*),
+        unit:units(*),
+        tags:item_tags(tag:tags(*))
+      `)
+      .single()
+
+    if (error) {
+      console.error('Error adding item:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Update inventory item
+   */
+  const updateInventoryItem = async (id: string, updates: InventoryItemUpdate) => {
+    const { data, error } = await supabase
+      .from('inventory_items')
+      .update(updates)
+      .eq('id', id)
+      .select(`
+        *,
+        product:products(*),
+        unit:units(*),
+        tags:item_tags(tag:tags(*))
+      `)
+      .single()
+
+    if (error) {
+      console.error('Error updating item:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Delete inventory item
+   */
+  const deleteInventoryItem = async (id: string) => {
+    // First delete associated tags
+    await supabase
+      .from('item_tags')
+      .delete()
+      .eq('item_id', id)
+
+    const { error } = await supabase
+      .from('inventory_items')
+      .delete()
+      .eq('id', id)
+
+    if (error) {
+      console.error('Error deleting item:', error)
+      return { error }
+    }
+
+    return { error: null }
+  }
+
+  /**
+   * Update item quantity (consume or restock)
+   */
+  const updateQuantity = async (id: string, change: number) => {
+    const { data: item, error: fetchError } = await getInventoryItem(id)
+    if (fetchError || !item) {
+      return { data: null, error: fetchError }
+    }
+
+    const newQuantity = Number(item.quantity) + change
+
+    if (newQuantity <= 0) {
+      // Auto-delete when quantity reaches zero
+      return await deleteInventoryItem(id)
+    }
+
+    return await updateInventoryItem(id, { quantity: newQuantity })
+  }
+
+  /**
+   * Add tags to item
+   */
+  const addItemTags = async (itemId: string, tagIds: string[]) => {
+    const items = tagIds.map(tagId => ({
+      item_id: itemId,
+      tag_id: tagId
+    }))
+
+    const { error } = await supabase
+      .from('item_tags')
+      .insert(items)
+
+    if (error) {
+      console.error('Error adding tags:', error)
+      return { error }
+    }
+
+    return { error: null }
+  }
+
+  /**
+   * Remove tag from item
+   */
+  const removeItemTag = async (itemId: string, tagId: string) => {
+    const { error } = await supabase
+      .from('item_tags')
+      .delete()
+      .eq('item_id', itemId)
+      .eq('tag_id', tagId)
+
+    if (error) {
+      console.error('Error removing tag:', error)
+      return { error }
+    }
+
+    return { error: null }
+  }
+
+  return {
+    getInventory,
+    getInventoryItem,
+    addInventoryItem,
+    updateInventoryItem,
+    deleteInventoryItem,
+    updateQuantity,
+    addItemTags,
+    removeItemTag
+  }
+}

app/composables/useTags.ts

@@ -0,0 +1,44 @@
+export const useTags = () => {
+  const supabase = useSupabase()
+
+  /**
+   * Get all tags
+   */
+  const getTags = async () => {
+    const { data, error } = await supabase
+      .from('tags')
+      .select('*')
+      .order('category', { ascending: true })
+      .order('name', { ascending: true })
+
+    if (error) {
+      console.error('Error fetching tags:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Get tags by category
+   */
+  const getTagsByCategory = async (category: 'position' | 'type' | 'dietary' | 'custom') => {
+    const { data, error } = await supabase
+      .from('tags')
+      .select('*')
+      .eq('category', category)
+      .order('name', { ascending: true })
+
+    if (error) {
+      console.error('Error fetching tags by category:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  return {
+    getTags,
+    getTagsByCategory
+  }
+}

app/composables/useUnits.ts

@@ -0,0 +1,53 @@
+export const useUnits = () => {
+  const supabase = useSupabase()
+
+  /**
+   * Get all units
+   */
+  const getUnits = async () => {
+    const { data, error } = await supabase
+      .from('units')
+      .select('*')
+      .order('unit_type', { ascending: true })
+      .order('name', { ascending: true })
+
+    if (error) {
+      console.error('Error fetching units:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Get default unit for a type
+   */
+  const getDefaultUnit = async (unitType: 'weight' | 'volume' | 'count' | 'custom') => {
+    const { data, error } = await supabase
+      .from('units')
+      .select('*')
+      .eq('unit_type', unitType)
+      .eq('is_default', true)
+      .single()
+
+    if (error) {
+      console.error('Error fetching default unit:', error)
+      return { data: null, error }
+    }
+
+    return { data, error: null }
+  }
+
+  /**
+   * Convert quantity between units
+   */
+  const convertUnit = (quantity: number, fromFactor: number, toFactor: number): number => {
+    return (quantity * fromFactor) / toFactor
+  }
+
+  return {
+    getUnits,
+    getDefaultUnit,
+    convertUnit
+  }
+}

app/pages/index.vue

@@ -17,36 +17,37 @@
           color="white" 
           size="lg"
           icon="i-heroicons-plus"
+          @click="showAddForm = true"
         >
           Add Manually
         </UButton>
       </div>
     </div>
 
-    <!-- Empty State -->
+    <!-- Add Item Form (Overlay) -->
-    <UCard v-if="true">
+    <div v-if="showAddForm" class="fixed inset-0 z-50 flex items-start justify-center pt-20 px-4 bg-black/50">
-      <div class="text-center py-12">
+      <div class="w-full max-w-lg">
-        <UIcon 
+        <AddItemForm 
-          name="i-heroicons-inbox" 
+          @close="showAddForm = false"
-          class="w-16 h-16 text-gray-400 mx-auto mb-4"
+          @added="handleItemAdded"
         />
-        <h3 class="text-lg font-semibold text-gray-900 mb-2">
-          No items yet
-        </h3>
-        <p class="text-gray-600 mb-6">
-          Start by scanning a barcode or adding an item manually.
-        </p>
-        <UButton 
-          to="/scan" 
-          color="primary"
-          icon="i-heroicons-qr-code"
-        >
-          Scan First Item
-        </UButton>
       </div>
-    </UCard>
+    </div>
 
-    <!-- TODO: Item list will go here -->
+    <!-- Edit Item Modal -->
+    <EditItemModal 
+      :item="editingItem"
+      @close="editingItem = null"
+      @updated="handleItemUpdated"
+    />
+
+    <!-- Inventory List -->
+    <InventoryList
+      ref="inventoryListRef"
+      :refresh="refreshKey"
+      @add-item="showAddForm = true"
+      @edit-item="editingItem = $event"
+    />
   </div>
 </template>
 
@@ -54,4 +55,20 @@
 definePageMeta({
   layout: 'default'
 })
+
+const showAddForm = ref(false)
+const editingItem = ref<any>(null)
+const refreshKey = ref(0)
+const inventoryListRef = ref()
+
+const handleItemAdded = (item: any) => {
+  showAddForm.value = false
+  // Reload the inventory list
+  inventoryListRef.value?.reload()
+}
+
+const handleItemUpdated = (item: any) => {
+  editingItem.value = null
+  inventoryListRef.value?.reload()
+}
 </script>

supabase/migrations/001_initial_schema.sql

@@ -0,0 +1,282 @@
+-- Migration: Initial database schema
+-- Created: 2026-02-09
+-- Issue: #13
+-- Description: Creates core tables for Pantry app (inventory, products, tags, units)
+
+-- ======================
+-- ENUM TYPES
+-- ======================
+
+CREATE TYPE tag_category AS ENUM (
+  'position',    -- Location: fridge, freezer, pantry
+  'type',        -- Food type: dairy, meat, vegan
+  'dietary',     -- Diet: gluten-free, vegan, organic
+  'custom'       -- User-defined
+);
+
+CREATE TYPE unit_type AS ENUM (
+  'weight',   -- kg, g, lb, oz
+  'volume',   -- L, mL, cup, tbsp
+  'count',    -- pcs, items (no conversion)
+  'custom'    -- can, jar, bottle (user-defined)
+);
+
+-- ======================
+-- BASE TABLES (no foreign keys)
+-- ======================
+
+-- Units: measurement units with conversion support
+CREATE TABLE units (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  
+  -- Core data
+  name TEXT NOT NULL,           -- "kilogram", "liter", "piece"
+  abbreviation TEXT NOT NULL,   -- "kg", "L", "pcs"
+  unit_type unit_type NOT NULL,
+  
+  -- Conversion system
+  base_unit_id UUID REFERENCES units(id),  -- NULL = this is a base unit
+  conversion_factor DECIMAL(20,10),        -- Factor to convert to base unit
+  
+  -- Metadata
+  is_default BOOLEAN DEFAULT false,  -- Shipped with app
+  created_by UUID REFERENCES auth.users(id),  -- NULL = system unit
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  
+  CONSTRAINT unique_unit_abbr UNIQUE (abbreviation, created_by),
+  CONSTRAINT check_conversion_logic CHECK (
+    (base_unit_id IS NULL AND conversion_factor IS NULL) OR 
+    (base_unit_id IS NOT NULL AND conversion_factor IS NOT NULL)
+  )
+);
+
+-- Tags: flexible labeling system
+CREATE TABLE tags (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  
+  -- Core data
+  name TEXT NOT NULL,
+  category tag_category NOT NULL DEFAULT 'custom',
+  
+  -- Visual
+  icon TEXT,    -- Emoji or icon name: "🧊", "cheese"
+  color TEXT,   -- Hex color: "#3b82f6"
+  
+  -- Ownership
+  created_by UUID REFERENCES auth.users(id),  -- NULL = system tag
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  
+  CONSTRAINT unique_tag_name UNIQUE (name, created_by)
+);
+
+-- ======================
+-- MAIN TABLES
+-- ======================
+
+-- Products: cached product data from Open Food Facts
+CREATE TABLE products (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  
+  -- Open Food Facts data
+  barcode TEXT UNIQUE NOT NULL,
+  name TEXT NOT NULL,
+  brand TEXT,
+  image_url TEXT,
+  image_small_url TEXT,  -- Thumbnail
+  
+  -- Categories from Open Food Facts
+  categories TEXT[],  -- Array: ['dairy', 'milk']
+  
+  -- Nutrition (optional, for future features)
+  nutrition JSONB,  -- Full nutrition data
+  
+  -- Defaults
+  default_unit_id UUID REFERENCES units(id),
+  default_quantity DECIMAL(10,2),  -- E.g., 1L bottle
+  
+  -- Metadata
+  source TEXT DEFAULT 'openfoodfacts',
+  cached_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  last_fetched TIMESTAMPTZ,
+  
+  -- Quality score (from Open Food Facts)
+  completeness_score INTEGER CHECK (completeness_score BETWEEN 0 AND 100)
+);
+
+-- Inventory Items: actual items in your kitchen right now
+CREATE TABLE inventory_items (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  
+  -- Product reference (nullable for custom items)
+  product_id UUID REFERENCES products(id) ON DELETE SET NULL,
+  
+  -- Core data
+  name TEXT NOT NULL,  -- Product name or custom name
+  quantity DECIMAL(10,2) NOT NULL CHECK (quantity >= 0),
+  unit_id UUID NOT NULL REFERENCES units(id),
+  
+  -- Optional metadata
+  expiry_date DATE,
+  location TEXT,  -- Free text: "top shelf", "door", etc.
+  notes TEXT,
+  
+  -- Audit trail
+  added_by UUID NOT NULL REFERENCES auth.users(id),
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Item Tags: many-to-many relationship between items and tags
+CREATE TABLE item_tags (
+  item_id UUID NOT NULL REFERENCES inventory_items(id) ON DELETE CASCADE,
+  tag_id UUID NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+  
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  
+  PRIMARY KEY (item_id, tag_id)
+);
+
+-- User Profiles: additional user metadata
+CREATE TABLE user_profiles (
+  id UUID PRIMARY KEY REFERENCES auth.users(id) ON DELETE CASCADE,
+  
+  display_name TEXT,
+  avatar_url TEXT,
+  
+  -- Preferences
+  default_unit_system TEXT DEFAULT 'metric',  -- 'metric' or 'imperial'
+  theme TEXT DEFAULT 'auto',                  -- 'light', 'dark', 'auto'
+  
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- ======================
+-- INDEXES
+-- ======================
+
+-- Units
+CREATE INDEX idx_units_type ON units(unit_type);
+CREATE INDEX idx_units_base ON units(base_unit_id);
+
+-- Tags
+CREATE INDEX idx_tags_category ON tags(category);
+CREATE INDEX idx_tags_created_by ON tags(created_by);
+
+-- Products
+CREATE UNIQUE INDEX idx_products_barcode ON products(barcode);
+CREATE INDEX idx_products_name ON products USING GIN (to_tsvector('english', name));
+CREATE INDEX idx_products_search ON products 
+  USING GIN (to_tsvector('english', name || ' ' || COALESCE(brand, '')));
+
+-- Inventory Items
+CREATE INDEX idx_items_product ON inventory_items(product_id);
+CREATE INDEX idx_items_added_by ON inventory_items(added_by);
+CREATE INDEX idx_items_expiry ON inventory_items(expiry_date) WHERE expiry_date IS NOT NULL;
+
+-- Item Tags
+CREATE INDEX idx_item_tags_tag ON item_tags(tag_id);
+CREATE INDEX idx_item_tags_item ON item_tags(item_id);
+
+-- ======================
+-- FUNCTIONS
+-- ======================
+
+-- Auto-update timestamp trigger function
+CREATE OR REPLACE FUNCTION update_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+  NEW.updated_at = NOW();
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Unit conversion function
+CREATE OR REPLACE FUNCTION convert_unit(
+  quantity DECIMAL,
+  from_unit_id UUID,
+  to_unit_id UUID
+)
+RETURNS DECIMAL AS $$
+DECLARE
+  from_factor DECIMAL;
+  to_factor DECIMAL;
+  from_type unit_type;
+  to_type unit_type;
+  base_quantity DECIMAL;
+BEGIN
+  -- Get unit types and conversion factors
+  SELECT unit_type, 
+         COALESCE(conversion_factor, 1.0) INTO from_type, from_factor
+  FROM units WHERE id = from_unit_id;
+  
+  SELECT unit_type,
+         COALESCE(conversion_factor, 1.0) INTO to_type, to_factor
+  FROM units WHERE id = to_unit_id;
+  
+  -- Check if units are compatible
+  IF from_type != to_type THEN
+    RAISE EXCEPTION 'Cannot convert between % and %', from_type, to_type;
+  END IF;
+  
+  -- Convert to base unit, then to target unit
+  base_quantity := quantity * from_factor;
+  RETURN base_quantity / to_factor;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE;
+
+-- Full-text search function for products
+CREATE OR REPLACE FUNCTION search_products(search_query TEXT)
+RETURNS TABLE (
+  id UUID,
+  barcode TEXT,
+  name TEXT,
+  brand TEXT,
+  rank REAL
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    p.id,
+    p.barcode,
+    p.name,
+    p.brand,
+    ts_rank(to_tsvector('english', p.name || ' ' || COALESCE(p.brand, '')), 
+            plainto_tsquery('english', search_query)) AS rank
+  FROM products p
+  WHERE to_tsvector('english', p.name || ' ' || COALESCE(p.brand, '')) 
+        @@ plainto_tsquery('english', search_query)
+  ORDER BY rank DESC
+  LIMIT 20;
+END;
+$$ LANGUAGE plpgsql;
+
+-- ======================
+-- TRIGGERS
+-- ======================
+
+-- Auto-update timestamp triggers
+CREATE TRIGGER update_items_updated_at
+  BEFORE UPDATE ON inventory_items
+  FOR EACH ROW
+  EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER update_profiles_updated_at
+  BEFORE UPDATE ON user_profiles
+  FOR EACH ROW
+  EXECUTE FUNCTION update_updated_at();
+
+-- ======================
+-- COMMENTS
+-- ======================
+
+COMMENT ON TABLE inventory_items IS 'Current inventory items in the kitchen';
+COMMENT ON TABLE products IS 'Cached product data from Open Food Facts';
+COMMENT ON TABLE tags IS 'Flexible labeling system for organization';
+COMMENT ON TABLE item_tags IS 'Many-to-many relationship between items and tags';
+COMMENT ON TABLE units IS 'Measurement units with conversion support';
+COMMENT ON TABLE user_profiles IS 'Additional user metadata and preferences';
+
+COMMENT ON FUNCTION update_updated_at() IS 'Automatically updates the updated_at timestamp';
+COMMENT ON FUNCTION convert_unit(DECIMAL, UUID, UUID) IS 'Converts quantity between compatible units';
+COMMENT ON FUNCTION search_products(TEXT) IS 'Full-text search for products by name and brand';

supabase/migrations/002_rls_policies.sql

@@ -0,0 +1,180 @@
+-- Migration: Row Level Security Policies
+-- Created: 2026-02-09
+-- Issue: #14
+-- Description: Enables RLS and creates security policies for all tables
+
+-- ======================
+-- ENABLE RLS
+-- ======================
+
+ALTER TABLE inventory_items ENABLE ROW LEVEL SECURITY;
+ALTER TABLE products ENABLE ROW LEVEL SECURITY;
+ALTER TABLE tags ENABLE ROW LEVEL SECURITY;
+ALTER TABLE item_tags ENABLE ROW LEVEL SECURITY;
+ALTER TABLE units ENABLE ROW LEVEL SECURITY;
+ALTER TABLE user_profiles ENABLE ROW LEVEL SECURITY;
+
+-- ======================
+-- INVENTORY_ITEMS POLICIES
+-- ======================
+
+-- Everyone can read (shared household inventory)
+CREATE POLICY "inventory_items_select_all" ON inventory_items
+  FOR SELECT
+  USING (true);
+
+-- Authenticated users can insert items
+CREATE POLICY "inventory_items_insert_auth" ON inventory_items
+  FOR INSERT
+  WITH CHECK (auth.uid() IS NOT NULL);
+
+-- Authenticated users can update any item
+CREATE POLICY "inventory_items_update_auth" ON inventory_items
+  FOR UPDATE
+  USING (auth.uid() IS NOT NULL);
+
+-- Authenticated users can delete any item
+CREATE POLICY "inventory_items_delete_auth" ON inventory_items
+  FOR DELETE
+  USING (auth.uid() IS NOT NULL);
+
+-- ======================
+-- PRODUCTS POLICIES
+-- ======================
+
+-- Everyone can read cached products
+CREATE POLICY "products_select_all" ON products
+  FOR SELECT
+  USING (true);
+
+-- Only service role can write (via Edge Functions)
+-- No user-level INSERT/UPDATE/DELETE policies
+
+-- ======================
+-- TAGS POLICIES
+-- ======================
+
+-- Everyone can read all tags
+CREATE POLICY "tags_select_all" ON tags
+  FOR SELECT
+  USING (true);
+
+-- Authenticated users can create tags
+CREATE POLICY "tags_insert_auth" ON tags
+  FOR INSERT
+  WITH CHECK (auth.uid() IS NOT NULL);
+
+-- Users can update their own tags OR system tags (created_by IS NULL)
+CREATE POLICY "tags_update_own" ON tags
+  FOR UPDATE
+  USING (
+    created_by = auth.uid() OR created_by IS NULL
+  );
+
+-- Users can only delete their own custom tags
+CREATE POLICY "tags_delete_own" ON tags
+  FOR DELETE
+  USING (created_by = auth.uid());
+
+-- ======================
+-- ITEM_TAGS POLICIES
+-- ======================
+
+-- Everyone can read
+CREATE POLICY "item_tags_select_all" ON item_tags
+  FOR SELECT
+  USING (true);
+
+-- Authenticated users can add tags to items
+CREATE POLICY "item_tags_insert_auth" ON item_tags
+  FOR INSERT
+  WITH CHECK (auth.uid() IS NOT NULL);
+
+-- Authenticated users can remove tags from items
+CREATE POLICY "item_tags_delete_auth" ON item_tags
+  FOR DELETE
+  USING (auth.uid() IS NOT NULL);
+
+-- ======================
+-- UNITS POLICIES
+-- ======================
+
+-- Everyone can read all units
+CREATE POLICY "units_select_all" ON units
+  FOR SELECT
+  USING (true);
+
+-- Authenticated users can create custom units (not default ones)
+CREATE POLICY "units_insert_auth" ON units
+  FOR INSERT
+  WITH CHECK (
+    auth.uid() IS NOT NULL AND is_default = false
+  );
+
+-- Users can update their own custom units only
+CREATE POLICY "units_update_own" ON units
+  FOR UPDATE
+  USING (
+    created_by = auth.uid() AND is_default = false
+  );
+
+-- Users can delete their own custom units only
+CREATE POLICY "units_delete_own" ON units
+  FOR DELETE
+  USING (
+    created_by = auth.uid() AND is_default = false
+  );
+
+-- ======================
+-- USER_PROFILES POLICIES
+-- ======================
+
+-- Users can read all profiles (for display names, avatars)
+CREATE POLICY "user_profiles_select_all" ON user_profiles
+  FOR SELECT
+  USING (true);
+
+-- Users can insert their own profile
+CREATE POLICY "user_profiles_insert_own" ON user_profiles
+  FOR INSERT
+  WITH CHECK (auth.uid() = id);
+
+-- Users can update only their own profile
+CREATE POLICY "user_profiles_update_own" ON user_profiles
+  FOR UPDATE
+  USING (auth.uid() = id);
+
+-- Users can delete only their own profile
+CREATE POLICY "user_profiles_delete_own" ON user_profiles
+  FOR DELETE
+  USING (auth.uid() = id);
+
+-- ======================
+-- COMMENTS
+-- ======================
+
+COMMENT ON POLICY "inventory_items_select_all" ON inventory_items IS 'Allow all users to view shared household inventory';
+COMMENT ON POLICY "inventory_items_insert_auth" ON inventory_items IS 'Authenticated users can add items';
+COMMENT ON POLICY "inventory_items_update_auth" ON inventory_items IS 'Authenticated users can update any item (shared inventory)';
+COMMENT ON POLICY "inventory_items_delete_auth" ON inventory_items IS 'Authenticated users can delete any item';
+
+COMMENT ON POLICY "products_select_all" ON products IS 'Allow all users to view cached product data';
+
+COMMENT ON POLICY "tags_select_all" ON tags IS 'Allow all users to view tags (system and custom)';
+COMMENT ON POLICY "tags_insert_auth" ON tags IS 'Authenticated users can create custom tags';
+COMMENT ON POLICY "tags_update_own" ON tags IS 'Users can update their own tags or system tags';
+COMMENT ON POLICY "tags_delete_own" ON tags IS 'Users can only delete their own custom tags';
+
+COMMENT ON POLICY "item_tags_select_all" ON item_tags IS 'Allow all users to view item tag associations';
+COMMENT ON POLICY "item_tags_insert_auth" ON item_tags IS 'Authenticated users can tag items';
+COMMENT ON POLICY "item_tags_delete_auth" ON item_tags IS 'Authenticated users can remove tags from items';
+
+COMMENT ON POLICY "units_select_all" ON units IS 'Allow all users to view all units';
+COMMENT ON POLICY "units_insert_auth" ON units IS 'Authenticated users can create custom units';
+COMMENT ON POLICY "units_update_own" ON units IS 'Users can only update their own custom units';
+COMMENT ON POLICY "units_delete_own" ON units IS 'Users can only delete their own custom units';
+
+COMMENT ON POLICY "user_profiles_select_all" ON user_profiles IS 'Allow users to view all profiles for display purposes';
+COMMENT ON POLICY "user_profiles_insert_own" ON user_profiles IS 'Users can create their own profile';
+COMMENT ON POLICY "user_profiles_update_own" ON user_profiles IS 'Users can only update their own profile';
+COMMENT ON POLICY "user_profiles_delete_own" ON user_profiles IS 'Users can only delete their own profile';

supabase/migrations/003_helper_functions.sql

@@ -0,0 +1,251 @@
+-- Migration: Additional SQL Functions for Inventory Management
+-- Week 2: Helper functions for common queries
+
+-- Function: Get inventory items with full details (tags, product info, unit conversion)
+CREATE OR REPLACE FUNCTION get_inventory_details()
+RETURNS TABLE (
+  item_id UUID,
+  item_name TEXT,
+  quantity DECIMAL,
+  unit_abbreviation TEXT,
+  unit_name TEXT,
+  expiry_date DATE,
+  days_until_expiry INTEGER,
+  tags TEXT[],
+  product_brand TEXT,
+  product_image_url TEXT,
+  product_barcode TEXT,
+  created_at TIMESTAMPTZ,
+  updated_at TIMESTAMPTZ
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    i.id AS item_id,
+    i.name AS item_name,
+    i.quantity,
+    u.abbreviation AS unit_abbreviation,
+    u.name AS unit_name,
+    i.expiry_date,
+    (i.expiry_date - CURRENT_DATE) AS days_until_expiry,
+    COALESCE(ARRAY_AGG(DISTINCT t.name) FILTER (WHERE t.name IS NOT NULL), '{}') AS tags,
+    p.brand AS product_brand,
+    p.image_url AS product_image_url,
+    p.barcode AS product_barcode,
+    i.created_at,
+    i.updated_at
+  FROM inventory_items i
+    JOIN units u ON i.unit_id = u.id
+    LEFT JOIN products p ON i.product_id = p.id
+    LEFT JOIN item_tags it ON i.id = it.item_id
+    LEFT JOIN tags t ON it.tag_id = t.id
+  GROUP BY 
+    i.id, i.name, i.quantity, u.abbreviation, u.name, 
+    i.expiry_date, p.brand, p.image_url, p.barcode, 
+    i.created_at, i.updated_at
+  ORDER BY i.created_at DESC;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION get_inventory_details() IS 'Returns all inventory items with denormalized data for display';
+
+-- Function: Get items expiring soon
+CREATE OR REPLACE FUNCTION get_expiring_items(days_ahead INTEGER DEFAULT 7)
+RETURNS TABLE (
+  item_id UUID,
+  item_name TEXT,
+  quantity DECIMAL,
+  unit_abbreviation TEXT,
+  expiry_date DATE,
+  days_until_expiry INTEGER,
+  tags TEXT[]
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    i.id AS item_id,
+    i.name AS item_name,
+    i.quantity,
+    u.abbreviation AS unit_abbreviation,
+    i.expiry_date,
+    (i.expiry_date - CURRENT_DATE) AS days_until_expiry,
+    COALESCE(ARRAY_AGG(DISTINCT t.name) FILTER (WHERE t.name IS NOT NULL), '{}') AS tags
+  FROM inventory_items i
+    JOIN units u ON i.unit_id = u.id
+    LEFT JOIN item_tags it ON i.id = it.item_id
+    LEFT JOIN tags t ON it.tag_id = t.id
+  WHERE 
+    i.expiry_date IS NOT NULL
+    AND i.expiry_date <= CURRENT_DATE + MAKE_INTERVAL(days => days_ahead)
+  GROUP BY i.id, i.name, i.quantity, u.abbreviation, i.expiry_date
+  ORDER BY i.expiry_date ASC;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION get_expiring_items(INTEGER) IS 'Returns items expiring within specified days (default 7)';
+
+-- Function: Get items by tag
+CREATE OR REPLACE FUNCTION get_items_by_tag(tag_name TEXT)
+RETURNS TABLE (
+  item_id UUID,
+  item_name TEXT,
+  quantity DECIMAL,
+  unit_abbreviation TEXT,
+  expiry_date DATE,
+  created_at TIMESTAMPTZ
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    i.id AS item_id,
+    i.name AS item_name,
+    i.quantity,
+    u.abbreviation AS unit_abbreviation,
+    i.expiry_date,
+    i.created_at
+  FROM inventory_items i
+    JOIN units u ON i.unit_id = u.id
+    JOIN item_tags it ON i.id = it.item_id
+    JOIN tags t ON it.tag_id = t.id
+  WHERE t.name ILIKE tag_name
+  ORDER BY i.created_at DESC;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION get_items_by_tag(TEXT) IS 'Returns all items with specified tag (case-insensitive)';
+
+-- Function: Get low stock items (quantity <= threshold)
+CREATE OR REPLACE FUNCTION get_low_stock_items(threshold DECIMAL DEFAULT 1.0)
+RETURNS TABLE (
+  item_id UUID,
+  item_name TEXT,
+  quantity DECIMAL,
+  unit_abbreviation TEXT,
+  tags TEXT[]
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    i.id AS item_id,
+    i.name AS item_name,
+    i.quantity,
+    u.abbreviation AS unit_abbreviation,
+    COALESCE(ARRAY_AGG(DISTINCT t.name) FILTER (WHERE t.name IS NOT NULL), '{}') AS tags
+  FROM inventory_items i
+    JOIN units u ON i.unit_id = u.id
+    LEFT JOIN item_tags it ON i.id = it.item_id
+    LEFT JOIN tags t ON it.tag_id = t.id
+  WHERE i.quantity <= threshold
+  GROUP BY i.id, i.name, i.quantity, u.abbreviation
+  ORDER BY i.quantity ASC, i.name ASC;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION get_low_stock_items(DECIMAL) IS 'Returns items with quantity at or below threshold';
+
+-- Function: Update item quantity (consume or restock)
+CREATE OR REPLACE FUNCTION update_item_quantity(
+  item_uuid UUID,
+  quantity_change DECIMAL,
+  delete_if_zero BOOLEAN DEFAULT TRUE
+)
+RETURNS BOOLEAN AS $$
+DECLARE
+  new_quantity DECIMAL;
+BEGIN
+  -- Calculate new quantity
+  SELECT quantity + quantity_change INTO new_quantity
+  FROM inventory_items
+  WHERE id = item_uuid;
+
+  IF new_quantity IS NULL THEN
+    RETURN FALSE;  -- Item not found
+  END IF;
+
+  -- Delete if zero and flag is set
+  IF new_quantity <= 0 AND delete_if_zero THEN
+    DELETE FROM inventory_items WHERE id = item_uuid;
+    RETURN TRUE;
+  END IF;
+
+  -- Update quantity (ensure non-negative)
+  UPDATE inventory_items
+  SET quantity = GREATEST(new_quantity, 0),
+      updated_at = NOW()
+  WHERE id = item_uuid;
+
+  RETURN TRUE;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION update_item_quantity(UUID, DECIMAL, BOOLEAN) IS 'Updates item quantity (positive for restock, negative for consume). Optionally deletes if zero.';
+
+-- Function: Get inventory statistics
+CREATE OR REPLACE FUNCTION get_inventory_stats()
+RETURNS TABLE (
+  total_items BIGINT,
+  total_unique_products BIGINT,
+  items_expiring_week BIGINT,
+  items_expired BIGINT,
+  total_tags_used BIGINT
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    COUNT(DISTINCT i.id) AS total_items,
+    COUNT(DISTINCT i.product_id) FILTER (WHERE i.product_id IS NOT NULL) AS total_unique_products,
+    COUNT(i.id) FILTER (
+      WHERE i.expiry_date IS NOT NULL 
+      AND i.expiry_date BETWEEN CURRENT_DATE AND CURRENT_DATE + INTERVAL '7 days'
+    ) AS items_expiring_week,
+    COUNT(i.id) FILTER (
+      WHERE i.expiry_date IS NOT NULL 
+      AND i.expiry_date < CURRENT_DATE
+    ) AS items_expired,
+    COUNT(DISTINCT it.tag_id) AS total_tags_used
+  FROM inventory_items i
+    LEFT JOIN item_tags it ON i.id = it.item_id;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION get_inventory_stats() IS 'Returns summary statistics for the entire inventory';
+
+-- Function: Search inventory (full-text search on items and products)
+CREATE OR REPLACE FUNCTION search_inventory(search_query TEXT)
+RETURNS TABLE (
+  item_id UUID,
+  item_name TEXT,
+  quantity DECIMAL,
+  unit_abbreviation TEXT,
+  product_brand TEXT,
+  tags TEXT[],
+  relevance REAL
+) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT 
+    i.id AS item_id,
+    i.name AS item_name,
+    i.quantity,
+    u.abbreviation AS unit_abbreviation,
+    p.brand AS product_brand,
+    COALESCE(ARRAY_AGG(DISTINCT t.name) FILTER (WHERE t.name IS NOT NULL), '{}') AS tags,
+    ts_rank(
+      to_tsvector('english', i.name || ' ' || COALESCE(p.brand, '') || ' ' || COALESCE(p.name, '')),
+      plainto_tsquery('english', search_query)
+    ) AS relevance
+  FROM inventory_items i
+    JOIN units u ON i.unit_id = u.id
+    LEFT JOIN products p ON i.product_id = p.id
+    LEFT JOIN item_tags it ON i.id = it.item_id
+    LEFT JOIN tags t ON it.tag_id = t.id
+  WHERE 
+    to_tsvector('english', i.name || ' ' || COALESCE(p.brand, '') || ' ' || COALESCE(p.name, ''))
+    @@ plainto_tsquery('english', search_query)
+  GROUP BY i.id, i.name, i.quantity, u.abbreviation, p.brand, p.name
+  ORDER BY relevance DESC, i.created_at DESC
+  LIMIT 50;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION search_inventory(TEXT) IS 'Full-text search across inventory items and products';

supabase/migrations/004_seed_units.sql

@@ -0,0 +1,37 @@
+-- Migration: Seed Default Units
+-- Week 2: Pre-populate common measurement units with conversions
+
+-- Weight units (metric base: gram)
+INSERT INTO units (id, name, abbreviation, unit_type, base_unit_id, conversion_factor, is_default, created_by) VALUES
+  ('f47ac10b-58cc-4372-a567-0e02b2c3d479', 'Gram', 'g', 'weight', NULL, 1.0, TRUE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440001', 'Kilogram', 'kg', 'weight', 'f47ac10b-58cc-4372-a567-0e02b2c3d479', 1000.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440002', 'Milligram', 'mg', 'weight', 'f47ac10b-58cc-4372-a567-0e02b2c3d479', 0.001, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440003', 'Pound', 'lb', 'weight', 'f47ac10b-58cc-4372-a567-0e02b2c3d479', 453.592, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440004', 'Ounce', 'oz', 'weight', 'f47ac10b-58cc-4372-a567-0e02b2c3d479', 28.3495, FALSE, NULL);
+
+-- Volume units (metric base: milliliter)
+INSERT INTO units (id, name, abbreviation, unit_type, base_unit_id, conversion_factor, is_default, created_by) VALUES
+  ('550e8400-e29b-41d4-a716-446655440010', 'Milliliter', 'mL', 'volume', NULL, 1.0, TRUE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440011', 'Liter', 'L', 'volume', '550e8400-e29b-41d4-a716-446655440010', 1000.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440012', 'Centiliter', 'cL', 'volume', '550e8400-e29b-41d4-a716-446655440010', 10.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440013', 'Deciliter', 'dL', 'volume', '550e8400-e29b-41d4-a716-446655440010', 100.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440014', 'Cup', 'cup', 'volume', '550e8400-e29b-41d4-a716-446655440010', 236.588, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440015', 'Tablespoon', 'tbsp', 'volume', '550e8400-e29b-41d4-a716-446655440010', 14.7868, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440016', 'Teaspoon', 'tsp', 'volume', '550e8400-e29b-41d4-a716-446655440010', 4.92892, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440017', 'Fluid Ounce', 'fl oz', 'volume', '550e8400-e29b-41d4-a716-446655440010', 29.5735, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440018', 'Gallon', 'gal', 'volume', '550e8400-e29b-41d4-a716-446655440010', 3785.41, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440019', 'Quart', 'qt', 'volume', '550e8400-e29b-41d4-a716-446655440010', 946.353, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440020', 'Pint', 'pt', 'volume', '550e8400-e29b-41d4-a716-446655440010', 473.176, FALSE, NULL);
+
+-- Count units (no conversions, each is independent)
+INSERT INTO units (id, name, abbreviation, unit_type, base_unit_id, conversion_factor, is_default, created_by) VALUES
+  ('550e8400-e29b-41d4-a716-446655440030', 'Piece', 'pc', 'count', NULL, 1.0, TRUE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440031', 'Dozen', 'doz', 'count', '550e8400-e29b-41d4-a716-446655440030', 12.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440032', 'Package', 'pkg', 'count', NULL, 1.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440033', 'Bottle', 'btl', 'count', NULL, 1.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440034', 'Can', 'can', 'count', NULL, 1.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440035', 'Jar', 'jar', 'count', NULL, 1.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440036', 'Box', 'box', 'count', NULL, 1.0, FALSE, NULL),
+  ('550e8400-e29b-41d4-a716-446655440037', 'Bag', 'bag', 'count', NULL, 1.0, FALSE, NULL);
+
+COMMENT ON TABLE units IS 'Measurement units with 30 common presets covering metric, imperial, and count units';

supabase/migrations/005_seed_tags.sql

@@ -0,0 +1,49 @@
+-- Migration: Seed Default Tags
+-- Week 2: Pre-populate common organizational tags
+
+-- Position Tags (where items are stored)
+INSERT INTO tags (id, name, category, icon, color, created_by) VALUES
+  ('650e8400-e29b-41d4-a716-446655440001', 'Fridge', 'position', '🧊', '#3b82f6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440002', 'Freezer', 'position', '❄️', '#06b6d4', NULL),
+  ('650e8400-e29b-41d4-a716-446655440003', 'Pantry', 'position', '🗄️', '#8b5cf6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440004', 'Cabinet', 'position', '🚪', '#6b7280', NULL),
+  ('650e8400-e29b-41d4-a716-446655440005', 'Countertop', 'position', '🍽️', '#f59e0b', NULL),
+  ('650e8400-e29b-41d4-a716-446655440006', 'Cellar', 'position', '🏚️', '#78350f', NULL);
+
+-- Type Tags (food categories)
+INSERT INTO tags (id, name, category, icon, color, created_by) VALUES
+  ('650e8400-e29b-41d4-a716-446655440010', 'Dairy', 'type', '🧀', '#fbbf24', NULL),
+  ('650e8400-e29b-41d4-a716-446655440011', 'Meat', 'type', '🥩', '#ef4444', NULL),
+  ('650e8400-e29b-41d4-a716-446655440012', 'Fish', 'type', '🐟', '#3b82f6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440013', 'Vegetables', 'type', '🥬', '#22c55e', NULL),
+  ('650e8400-e29b-41d4-a716-446655440014', 'Fruits', 'type', '🍎', '#f97316', NULL),
+  ('650e8400-e29b-41d4-a716-446655440015', 'Grains', 'type', '🌾', '#eab308', NULL),
+  ('650e8400-e29b-41d4-a716-446655440016', 'Legumes', 'type', '🫘', '#84cc16', NULL),
+  ('650e8400-e29b-41d4-a716-446655440017', 'Condiments', 'type', '🧂', '#ef4444', NULL),
+  ('650e8400-e29b-41d4-a716-446655440018', 'Snacks', 'type', '🍿', '#f97316', NULL),
+  ('650e8400-e29b-41d4-a716-446655440019', 'Beverages', 'type', '🥤', '#06b6d4', NULL),
+  ('650e8400-e29b-41d4-a716-446655440020', 'Baking', 'type', '🧁', '#ec4899', NULL),
+  ('650e8400-e29b-41d4-a716-446655440021', 'Spices', 'type', '🌶️', '#dc2626', NULL),
+  ('650e8400-e29b-41d4-a716-446655440022', 'Canned', 'type', '🥫', '#71717a', NULL),
+  ('650e8400-e29b-41d4-a716-446655440023', 'Frozen', 'type', '🧊', '#06b6d4', NULL);
+
+-- Dietary Tags
+INSERT INTO tags (id, name, category, icon, color, created_by) VALUES
+  ('650e8400-e29b-41d4-a716-446655440030', 'Vegan', 'dietary', '🌱', '#22c55e', NULL),
+  ('650e8400-e29b-41d4-a716-446655440031', 'Vegetarian', 'dietary', '🥕', '#84cc16', NULL),
+  ('650e8400-e29b-41d4-a716-446655440032', 'Gluten-Free', 'dietary', '🌾', '#eab308', NULL),
+  ('650e8400-e29b-41d4-a716-446655440033', 'Lactose-Free', 'dietary', '🥛', '#60a5fa', NULL),
+  ('650e8400-e29b-41d4-a716-446655440034', 'Organic', 'dietary', '♻️', '#10b981', NULL),
+  ('650e8400-e29b-41d4-a716-446655440035', 'Low-Carb', 'dietary', '🥗', '#22c55e', NULL),
+  ('650e8400-e29b-41d4-a716-446655440036', 'Kosher', 'dietary', '✡️', '#3b82f6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440037', 'Halal', 'dietary', '☪️', '#22c55e', NULL);
+
+-- Custom/Workflow Tags
+INSERT INTO tags (id, name, category, icon, color, created_by) VALUES
+  ('650e8400-e29b-41d4-a716-446655440040', 'Low Stock', 'custom', '⚠️', '#ef4444', NULL),
+  ('650e8400-e29b-41d4-a716-446655440041', 'To Buy', 'custom', '🛒', '#3b82f6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440042', 'Meal Prep', 'custom', '🍱', '#8b5cf6', NULL),
+  ('650e8400-e29b-41d4-a716-446655440043', 'Leftovers', 'custom', '♻️', '#f59e0b', NULL),
+  ('650e8400-e29b-41d4-a716-446655440044', 'Opening Soon', 'custom', '📆', '#f97316', NULL);
+
+COMMENT ON TABLE tags IS 'Pre-populated with 33 common tags across position, type, dietary, and workflow categories';