PHASE 2: Implements balance assertions for reconciliation

Adds balance assertion functionality to enable admins to verify accounting accuracy.

This includes:
- A new `balance_assertions` table in the database
- CRUD operations for balance assertions (create, get, list, check, delete)
- API endpoints for managing balance assertions (admin only)
- UI elements for creating, viewing, and re-checking assertions

Also, reorders the implementation roadmap in the documentation to reflect better the dependencies between phases.

static/js/index.js

@@ -65,7 +65,18 @@ window.app = Vue.createApp({
         loading: false
       },
       manualPaymentRequests: [],
-      pendingExpenses: []
+      pendingExpenses: [],
+      balanceAssertions: [],
+      assertionDialog: {
+        show: false,
+        account_id: '',
+        expected_balance_sats: null,
+        expected_balance_fiat: null,
+        fiat_currency: null,
+        tolerance_sats: 0,
+        tolerance_fiat: 0,
+        loading: false
+      }
     }
   },
   watch: {
@@ -115,6 +126,15 @@ window.app = Vue.createApp({
     },
     pendingManualPaymentRequests() {
       return this.manualPaymentRequests.filter(r => r.status === 'pending')
+    },
+    failedAssertions() {
+      return this.balanceAssertions.filter(a => a.status === 'failed')
+    },
+    passedAssertions() {
+      return this.balanceAssertions.filter(a => a.status === 'passed')
+    },
+    allAccounts() {
+      return this.accounts
     }
   },
   methods: {
@@ -579,6 +599,145 @@ window.app = Vue.createApp({
         LNbits.utils.notifyApiError(error)
       }
     },
+    async loadBalanceAssertions() {
+      if (!this.isSuperUser) return
+
+      try {
+        const response = await LNbits.api.request(
+          'GET',
+          '/castle/api/v1/assertions',
+          this.g.user.wallets[0].adminkey
+        )
+        this.balanceAssertions = response.data
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      }
+    },
+    async submitAssertion() {
+      this.assertionDialog.loading = true
+      try {
+        const payload = {
+          account_id: this.assertionDialog.account_id,
+          expected_balance_sats: this.assertionDialog.expected_balance_sats,
+          tolerance_sats: this.assertionDialog.tolerance_sats || 0
+        }
+
+        // Add fiat balance check if currency selected
+        if (this.assertionDialog.fiat_currency) {
+          payload.fiat_currency = this.assertionDialog.fiat_currency
+          payload.expected_balance_fiat = this.assertionDialog.expected_balance_fiat
+          payload.tolerance_fiat = this.assertionDialog.tolerance_fiat || 0
+        }
+
+        await LNbits.api.request(
+          'POST',
+          '/castle/api/v1/assertions',
+          this.g.user.wallets[0].adminkey,
+          payload
+        )
+
+        this.$q.notify({
+          type: 'positive',
+          message: 'Balance assertion passed!',
+          timeout: 3000
+        })
+
+        // Reset dialog
+        this.assertionDialog = {
+          show: false,
+          account_id: '',
+          expected_balance_sats: null,
+          expected_balance_fiat: null,
+          fiat_currency: null,
+          tolerance_sats: 0,
+          tolerance_fiat: 0,
+          loading: false
+        }
+
+        // Reload assertions
+        await this.loadBalanceAssertions()
+      } catch (error) {
+        // Check if it's a 409 Conflict (assertion failed)
+        if (error.response && error.response.status === 409) {
+          const detail = error.response.data.detail
+          this.$q.notify({
+            type: 'negative',
+            message: `Assertion Failed! Expected: ${this.formatSats(detail.expected_sats)} sats, Got: ${this.formatSats(detail.actual_sats)} sats (diff: ${this.formatSats(detail.difference_sats)} sats)`,
+            timeout: 5000,
+            html: true
+          })
+          // Still reload to show the failed assertion
+          await this.loadBalanceAssertions()
+          this.assertionDialog.show = false
+        } else {
+          LNbits.utils.notifyApiError(error)
+        }
+      } finally {
+        this.assertionDialog.loading = false
+      }
+    },
+    async recheckAssertion(assertionId) {
+      // Set loading state
+      const assertion = this.balanceAssertions.find(a => a.id === assertionId)
+      if (assertion) {
+        this.$set(assertion, 'rechecking', true)
+      }
+
+      try {
+        await LNbits.api.request(
+          'POST',
+          `/castle/api/v1/assertions/${assertionId}/check`,
+          this.g.user.wallets[0].adminkey
+        )
+
+        this.$q.notify({
+          type: 'positive',
+          message: 'Assertion re-checked',
+          timeout: 2000
+        })
+
+        await this.loadBalanceAssertions()
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      } finally {
+        if (assertion) {
+          this.$set(assertion, 'rechecking', false)
+        }
+      }
+    },
+    async deleteAssertion(assertionId) {
+      // Set loading state
+      const assertion = this.balanceAssertions.find(a => a.id === assertionId)
+      if (assertion) {
+        this.$set(assertion, 'deleting', true)
+      }
+
+      try {
+        await LNbits.api.request(
+          'DELETE',
+          `/castle/api/v1/assertions/${assertionId}`,
+          this.g.user.wallets[0].adminkey
+        )
+
+        this.$q.notify({
+          type: 'positive',
+          message: 'Assertion deleted',
+          timeout: 2000
+        })
+
+        await this.loadBalanceAssertions()
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      } finally {
+        if (assertion) {
+          this.$set(assertion, 'deleting', false)
+        }
+      }
+    },
+    getAccountName(accountId) {
+      const account = this.accounts.find(a => a.id === accountId)
+      return account ? account.name : accountId
+    },
     copyToClipboard(text) {
       navigator.clipboard.writeText(text)
       this.$q.notify({
@@ -730,6 +889,7 @@ window.app = Vue.createApp({
     if (this.isSuperUser) {
       await this.loadUsers()
       await this.loadPendingExpenses()
+      await this.loadBalanceAssertions()
     }
   }
 })