feat: add TagManager and tag filtering (#30 #31)

Issue #30 - TagManager component:
- Create/delete tags with name, category, icon, color
- Color picker with hex input
- Organized display by category
- Integrated in settings page with tabs

Issue #31 - Tag filter for inventory:
- TagFilter component with multi-select
- Filter button in inventory header
- Active filter display with removable badges
- Filters items by selected tags (OR logic)
- Clean "Clear" button

Updates:
- Extended useTags composable with createTag, deleteTag
- Enhanced settings page with tab navigation
- Improved inventory filtering UX

Closes #30, #31

app/components/inventory/InventoryList.vue

@@ -43,7 +43,7 @@
     <!-- 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"
+        v-for="item in filteredItems"
         :key="item.id"
         :item="item"
         @edit="$emit('edit-item', item)"
@@ -59,6 +59,7 @@ const { getInventory, deleteInventoryItem, updateQuantity } = useInventory()
 
 const props = defineProps<{
   refresh?: boolean
+  tagFilters?: string[]
 }>()
 
 const emit = defineEmits<{
@@ -86,6 +87,21 @@ const loadInventory = async () => {
   loading.value = false
 }
 
+// Computed filtered items
+const filteredItems = computed(() => {
+  if (!props.tagFilters || props.tagFilters.length === 0) {
+    return items.value
+  }
+
+  // Filter items that have at least one of the selected tags
+  return items.value.filter(item => {
+    if (!item.tags || item.tags.length === 0) return false
+    
+    const itemTagIds = item.tags.map((t: any) => t.tag.id)
+    return props.tagFilters!.some(filterId => itemTagIds.includes(filterId))
+  })
+})
+
 const handleDelete = async (id: string) => {
   if (!confirm('Are you sure you want to delete this item?')) {
     return