Add tax treatment classification for investment accounts with international support (#693)

* Add tax treatment support for accounts, investments, and cryptos

* Replace hardcoded region labels with I18n translations

* Add I18n support for subtype labels with fallback to hardcoded values

* fixed schema

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Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>

app/views/accounts/_tax_treatment_badge.html.erb

@@ -0,0 +1,17 @@
+<%# locals: (account:) %>
+<%
+  treatment = account.tax_treatment
+  badge_classes = case treatment
+  when :tax_exempt
+    "bg-green-500/10 text-green-600 theme-dark:text-green-400"
+  when :tax_deferred
+    "bg-blue-500/10 text-blue-600 theme-dark:text-blue-400"
+  when :tax_advantaged
+    "bg-purple-500/10 text-purple-600 theme-dark:text-purple-400"
+  else
+    "bg-gray-500/10 text-secondary"
+  end
+%>
+<span class="inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium <%= badge_classes %>" title="<%= t("accounts.tax_treatment_descriptions.#{treatment}") %>">
+  <%= account.tax_treatment_label %>
+</span>

app/views/accounts/show/_header.html.erb

@@ -9,6 +9,9 @@
         <div class="truncate">
           <div class="flex items-center gap-3">
             <h2 class="font-medium text-xl truncate <%= "animate-pulse" if account.syncing? %>"><%= title %></h2>
+            <% if account.tax_treatment.present? %>
+              <%= render partial: "accounts/tax_treatment_badge", locals: { account: account } %>
+            <% end %>
             <% if account.draft? %>
               <%= render DS::Link.new(
                   text: "Complete setup",