Improve investment activity labels UX and add convert-to-trade feature (#649)

* Add `investment_activity_label` to trades and enhance activity label handling

- Introduced `investment_activity_label` column to the `trades` table with a migration.
- Backfilled existing `trades` with activity labels based on quantity (`Buy`, `Sell`, or `Other`).
- Replaced `category_id` in trades with `investment_activity_label` for better alignment with transaction labels.
- Updated views and controllers to display and manage activity labels for trades.
- Added localized badge components for displaying and editing labels dynamically.
- Enhanced `PlaidAccount::Investments::TransactionsProcessor` to assign and process activity labels automatically.
- Added investment flows section to reports for tracking contributions and withdrawals.
- Refactored related tests and models for consistency and to ensure proper validation and filtering.

* Improve handling of `investment_activity_label`, trade type, and security selection in trades and transactions

- Refined label assignment logic in `trades_controller` to default to `Buy`/`Sell` based on transaction nature.
- Simplified security selection in `transactions_controller` by resolving via unique IDs or custom tickers.
- Streamlined UI for trade and transaction forms by updating dropdown options and label text.
- Enabled quick-edit badges to open `convert_to_trade` modal when applicable, enhancing flexibility.
- Adjusted tests and views to align with updated workflows and ensure consistent behavior.

* Improve handling of `investment_activity_label`, trade type, and security selection in trades and transactions

- Refined label assignment logic in `trades_controller` to default to `Buy`/`Sell` based on transaction nature.
- Simplified security selection in `transactions_controller` by resolving via unique IDs or custom tickers.
- Streamlined UI for trade and transaction forms by updating dropdown options and label text.
- Enabled quick-edit badges to open `convert_to_trade` modal when applicable, enhancing flexibility.
- Adjusted tests and views to align with updated workflows and ensure consistent behavior.

* Improve handling of `investment_activity_label`, trade type, and security selection in trades and transactions

- Refined label assignment logic in `trades_controller` to default to `Buy`/`Sell` based on transaction nature.
- Simplified security selection in `transactions_controller` by resolving via unique IDs or custom tickers.
- Streamlined UI for trade and transaction forms by updating dropdown options and label text.
- Enabled quick-edit badges to open `convert_to_trade` modal when applicable, enhancing flexibility.
- Adjusted tests and views to align with updated workflows and ensure consistent behavior.

* Add safeguard for `dropdownTarget` existence in quick edit controller

- Prevent errors by ensuring `dropdownTarget` is present before toggling its visibility.

* Fix undefined method 'category' for Trade on mobile view

Trade model uses investment_activity_label, not category. The upstream
merge introduced a call to trade.category which doesn't exist. Use the
activity label badge on mobile instead.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix activity label logic for zero/blank quantity and sell inference

- Return `nil` for blank or zero quantity in `investment_activity_label_for`.
- Correct `is_sell` logic to use the amount’s sign properly in `transactions_controller`.

* Fix i18n key paths in transactions controller for convert_to_trade

- Update flash message translations to use full i18n paths.
- Use `BigDecimal` for quantity and price calculations to improve precision.

---------

Co-authored-by: Josh Waldrep <joshua.waldrep5+github@gmail.com>
Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

app/views/pages/dashboard/_investment_summary.html.erb

@@ -77,21 +77,40 @@
 
     <%# Investment Activity Summary %>
     <% totals = investment_statement.totals(period: period) %>
-    <% if totals.trades_count > 0 %>
-      <div class="px-4 pt-2">
-        <p class="text-xs text-secondary uppercase font-medium mb-2"><%= t(".period_activity", period: period.label) %></p>
-        <div class="flex gap-4 text-sm">
-          <div>
-            <span class="text-secondary"><%= t(".contributions") %>:</span>
-            <span class="font-medium text-primary"><%= format_money(totals.contributions) %></span>
-          </div>
-          <div>
-            <span class="text-secondary"><%= t(".withdrawals") %>:</span>
-            <span class="font-medium text-primary"><%= format_money(totals.withdrawals) %></span>
-          </div>
-          <div>
-            <span class="text-secondary"><%= t(".trades") %>:</span>
-            <span class="font-medium text-primary"><%= totals.trades_count %></span>
+    <% if totals.trades_count > 0 || totals.contributions.to_f > 0 || totals.withdrawals.to_f > 0 %>
+      <div class="bg-container-inset rounded-xl p-1 mx-4">
+        <div class="px-4 py-2 flex items-center uppercase text-xs font-medium text-secondary">
+          <%= t(".period_activity", period: period.label) %>
+        </div>
+        <div class="shadow-border-xs rounded-lg bg-container font-medium text-sm">
+          <div class="p-4 flex items-center justify-between gap-4">
+            <div class="flex items-center gap-2">
+              <div class="w-8 h-8 rounded-full bg-green-500/10 flex items-center justify-center">
+                <%= icon "trending-up", size: "sm", color: "green" %>
+              </div>
+              <div>
+                <p class="text-xs text-secondary"><%= t(".contributions") %></p>
+                <p class="font-medium text-green-600"><%= format_money(totals.contributions) %></p>
+              </div>
+            </div>
+            <div class="flex items-center gap-2">
+              <div class="w-8 h-8 rounded-full bg-orange-500/10 flex items-center justify-center">
+                <%= icon "trending-down", size: "sm", color: "orange" %>
+              </div>
+              <div>
+                <p class="text-xs text-secondary"><%= t(".withdrawals") %></p>
+                <p class="font-medium text-orange-600"><%= format_money(totals.withdrawals) %></p>
+              </div>
+            </div>
+            <div class="flex items-center gap-2">
+              <div class="w-8 h-8 rounded-full bg-blue-500/10 flex items-center justify-center">
+                <%= icon "arrow-left-right", size: "sm", color: "blue" %>
+              </div>
+              <div>
+                <p class="text-xs text-secondary"><%= t(".trades") %></p>
+                <p class="font-medium text-primary"><%= totals.trades_count %></p>
+              </div>
+            </div>
           </div>
         </div>
       </div>