feat: restructure UI with tab-based navigation (#119)

Reorganizes the merchant dashboard into a tab-based layout:
- Tabs: Merchant | Shipping | Stalls | Products | Messages | Orders
- Publish dropdown with NIP-15 options (NIP-99 disabled/coming soon)
- Consistent UI patterns across all tabs:
  - Search/filter/buttons aligned right
  - Actions column on right side of tables
  - Equal-width tabs
- Stalls tab: popup edit dialog, navigation to Products/Orders
- Products tab: filter icon dropdown for stall filtering
- Modular component structure for each tab section
- Fixed product API calls to use correct endpoints

Closes #119

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/components/shipping-zones-list.js

@@ -0,0 +1,203 @@
+window.app.component('shipping-zones-list', {
+  name: 'shipping-zones-list',
+  props: ['adminkey', 'inkey'],
+  template: '#shipping-zones-list',
+  delimiters: ['${', '}'],
+  data: function () {
+    return {
+      zones: [],
+      zoneDialog: {
+        showDialog: false,
+        data: {
+          id: null,
+          name: '',
+          countries: [],
+          cost: 0,
+          currency: 'sat'
+        }
+      },
+      currencies: [],
+      shippingZoneOptions: [
+        'Free (digital)',
+        'Flat rate',
+        'Worldwide',
+        'Europe',
+        'Australia',
+        'Austria',
+        'Belgium',
+        'Brazil',
+        'Canada',
+        'Denmark',
+        'Finland',
+        'France',
+        'Germany',
+        'Greece',
+        'Hong Kong',
+        'Hungary',
+        'Ireland',
+        'Indonesia',
+        'Israel',
+        'Italy',
+        'Japan',
+        'Kazakhstan',
+        'Korea',
+        'Luxembourg',
+        'Malaysia',
+        'Mexico',
+        'Netherlands',
+        'New Zealand',
+        'Norway',
+        'Poland',
+        'Portugal',
+        'Romania',
+        'Russia',
+        'Saudi Arabia',
+        'Singapore',
+        'Spain',
+        'Sweden',
+        'Switzerland',
+        'Thailand',
+        'Turkey',
+        'Ukraine',
+        'United Kingdom**',
+        'United States***',
+        'Vietnam',
+        'China'
+      ],
+      zonesTable: {
+        columns: [
+          {
+            name: 'name',
+            align: 'left',
+            label: 'Name',
+            field: 'name'
+          },
+          {
+            name: 'countries',
+            align: 'left',
+            label: 'Countries',
+            field: 'countries'
+          },
+          {
+            name: 'currency',
+            align: 'left',
+            label: 'Currency',
+            field: 'currency'
+          },
+          {
+            name: 'cost',
+            align: 'left',
+            label: 'Cost',
+            field: 'cost'
+          },
+          {
+            name: 'actions',
+            align: 'right',
+            label: 'Actions',
+            field: ''
+          }
+        ],
+        pagination: {
+          rowsPerPage: 10
+        }
+      }
+    }
+  },
+  methods: {
+    openZoneDialog: function (data) {
+      data = data || {
+        id: null,
+        name: '',
+        countries: [],
+        cost: 0,
+        currency: 'sat'
+      }
+      this.zoneDialog.data = {...data}
+      this.zoneDialog.showDialog = true
+    },
+    getZones: async function () {
+      try {
+        const {data} = await LNbits.api.request(
+          'GET',
+          '/nostrmarket/api/v1/zone',
+          this.inkey
+        )
+        this.zones = data
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      }
+    },
+    sendZoneFormData: async function () {
+      this.zoneDialog.showDialog = false
+      if (this.zoneDialog.data.id) {
+        await this.updateShippingZone(this.zoneDialog.data)
+      } else {
+        await this.createShippingZone(this.zoneDialog.data)
+      }
+      await this.getZones()
+    },
+    createShippingZone: async function (newZone) {
+      try {
+        await LNbits.api.request(
+          'POST',
+          '/nostrmarket/api/v1/zone',
+          this.adminkey,
+          newZone
+        )
+        this.$q.notify({
+          type: 'positive',
+          message: 'Zone created!'
+        })
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      }
+    },
+    updateShippingZone: async function (updatedZone) {
+      try {
+        await LNbits.api.request(
+          'PATCH',
+          `/nostrmarket/api/v1/zone/${updatedZone.id}`,
+          this.adminkey,
+          updatedZone
+        )
+        this.$q.notify({
+          type: 'positive',
+          message: 'Zone updated!'
+        })
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      }
+    },
+    confirmDeleteZone: function (zone) {
+      LNbits.utils
+        .confirmDialog(`Are you sure you want to delete zone "${zone.name}"?`)
+        .onOk(async () => {
+          await this.deleteShippingZone(zone.id)
+        })
+    },
+    deleteShippingZone: async function (zoneId) {
+      try {
+        await LNbits.api.request(
+          'DELETE',
+          `/nostrmarket/api/v1/zone/${zoneId}`,
+          this.adminkey
+        )
+        this.$q.notify({
+          type: 'positive',
+          message: 'Zone deleted!'
+        })
+        await this.getZones()
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      }
+    },
+    getCurrencies() {
+      const currencies = window.g.allowedCurrencies || []
+      this.currencies = ['sat', ...currencies]
+    }
+  },
+  created: async function () {
+    await this.getZones()
+    this.getCurrencies()
+  }
+})