Transaction transfers, payments, and matching (#883)

* Add transfer model and clean up family snapshot fixtures

* Ignore transfers in income and expense snapshots

* Add transfer validations

* Implement basic transfer matching UI

* Fix merge conflicts

* Add missing translations

* Tweak selection states for transfer types

* Add missing i18n translation

app/views/transfers/new.html.erb

@@ -0,0 +1,17 @@
+<%= modal do %>
+  <article class="mx-auto p-4 space-y-4 w-screen max-w-xl">
+    <header class="flex justify-between">
+      <%= tag.h2 t(".title"), class: "font-medium text-xl" %>
+      <%= lucide_icon "x", class: "w-5 h-5 text-gray-500", data: { action: "click->modal#close" } %>
+    </header>
+
+    <% if @transfer.errors.present? %>
+      <div class="text-red-600 flex items-center gap-2">
+        <%= lucide_icon "circle-alert", class: "w-5 h-5" %>
+        <p class="text-sm"><%= @transfer.errors.full_messages.to_sentence %></p>
+      </div>
+    <% end %>
+
+    <%= render "form", transfer: @transfer %>
+  </article>
+<% end %>