Fix transaction action buttons layout and Dashboard UTC error

Wrap edit/delete buttons in a flex container so they render
side by side instead of stacking. Fix Dashboard DateTime to use
UTC kind, which Npgsql requires for timestamp comparisons.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/views/transactions/TransactionsView.vue

@@ -82,8 +82,10 @@
           </tr>
         </template>
         <template #item.actions="{ item }">
+          <div class="d-flex">
             <v-btn icon size="x-small" variant="text" @click="editTransaction(item)"><v-icon size="small">mdi-pencil</v-icon></v-btn>
             <v-btn icon size="x-small" variant="text" color="error" @click="deleteTransaction(item.id)"><v-icon size="small">mdi-delete</v-icon></v-btn>
+          </div>
         </template>
       </v-data-table>
     </v-card>

src/Purrse.Api/Services/DashboardService.cs

@@ -27,7 +27,7 @@ public class DashboardService : IDashboardService
         var accountSummaries = accounts.Select(a => new AccountSummaryResponse(a.Id, a.Name, a.Type, a.Institution, a.Balance, a.CreditLimit)).ToList();
 
         var now = DateTime.UtcNow;
-        var startOfMonth = new DateTime(now.Year, now.Month, 1);
+        var startOfMonth = new DateTime(now.Year, now.Month, 1, 0, 0, 0, DateTimeKind.Utc);
         var startOfLastMonth = startOfMonth.AddMonths(-1);
 
         var recentTxns = await _db.Transactions