feat(financial): adiciona card de valor total do estoque no dashboard

Novo FinancialCard 'Valor Total do Estoque' consumindo overview.stock_value
da API, ao lado do Saldo Bancário Total.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/pages/financial/FinancialPage.vue

@@ -66,6 +66,12 @@
         :financial-value="overview.bank_balance_total"
         :hide-values="!showValues"
       />
+      <FinancialCard
+        title="Valor Total do Estoque"
+        icon="mdi-package-variant-closed"
+        :financial-value="overview.stock_value"
+        :hide-values="!showValues"
+      />
     </div>
 
     <div class="row q-px-md q-gutter-md q-mt-none">
@@ -101,6 +107,7 @@ function emptyOverview() {
     accounts_payable: { value: 0, count: 0 },
     accounts_receivable: { value: 0, count: 0 },
     bank_balance_total: 0,
+    stock_value: 0,
     last_transactions: [],
     franchise_performance: [],
   };