Add pending transaction handling and duplicate reconciliation logic (#602)

* Add pending transaction handling and duplicate reconciliation logic

- Implemented logic to exclude pending transactions from budgets and analytics calculations.
- Introduced mechanisms for reconciling pending transactions with posted versions.
- Added duplicate detection with support for merging or dismissing matches.
- Updated transaction search filters to include a `status_filter` for pending/confirmed transactions.
- Introduced UI elements for reviewing and resolving duplicates.
- Enhanced `ProviderSyncSummary` with stats for reconciled and stale pending transactions.

* Refactor translation handling and enhance transaction and sync logic

- Moved hardcoded strings to locale files for improved translation support.
- Refined styling for duplicate transaction indicators and sync summaries.
- Improved logic for excluding stale pending transactions and updating timestamps on batch exclusion.
- Added unique IDs to status filters for better element targeting in UI.
- Optimized database queries to avoid N+1 issues in stale pending calculations.

* Add sync settings and enhance pending transaction handling

- Introduced a new "Sync Settings" section in hosting settings with UI to toggle inclusion of pending transactions.
- Updated handling of pending transactions with improved inference logic for `posted=0` and `transacted_at` in processors.
- Added priority order for pending transaction inclusion: explicit argument > environment variable > runtime configurable setting.
- Refactored settings and controllers to store updated sync preferences.

* Refactor sync settings and pending transaction reconciliation

- Extracted logic for pending transaction reconciliation, stale exclusion, and unmatched tracking into dedicated methods for better maintainability.
- Updated sync settings to infer defaults from multiple provider environment variables (`SIMPLEFIN_INCLUDE_PENDING`, `PLAID_INCLUDE_PENDING`).
- Refined UI and messaging to handle multi-provider configurations in sync settings.

# Conflicts:
#	app/models/simplefin_item/importer.rb

* Debounce transaction reconciliation during imports

- Added per-run reconciliation debouncing to prevent repeated scans for the same account during chunked history imports.
- Trimmed size of reconciliation stats to retain recent details only.
- Introduced error tracking for reconciliation steps to improve UI visibility of issues.

* Apply ABS() in pending transaction queries and improve error handling

- Updated pending transaction logic to use ABS() for consistent handling of negative amounts.
- Adjusted amount bounds calculations to ensure accuracy for both positive and negative values.
- Refined exception handling in `merge_duplicate` to log failures and update user alert.
- Replaced `Date.today` with `Date.current` in tests to ensure timezone consistency.
- Minor optimization to avoid COUNT queries by loading limited records directly.

* Improve error handling in duplicate suggestion and dismissal logic

- Added exception handling for `store_duplicate_suggestion` to log failures and prevent crashes during fuzzy/low-confidence matches.
- Enhanced `dismiss_duplicate` action to handle `ActiveRecord::RecordInvalid` and display appropriate user alerts.

---------

Co-authored-by: Josh Waldrep <joshua.waldrep5+github@gmail.com>

app/views/transactions/show.html.erb

@@ -4,6 +4,47 @@
   <% end %>
 
   <% dialog.with_body do %>
+    <%# Potential duplicate alert %>
+    <% if @entry.transaction.has_potential_duplicate? %>
+      <% potential_match = @entry.transaction.potential_duplicate_entry %>
+      <% if potential_match %>
+        <div class="mx-4 my-3 p-4 rounded-lg border border-warning bg-warning/5">
+          <div class="flex items-start gap-3">
+            <%= icon "alert-triangle", size: "md", color: "warning" %>
+            <div class="flex-1 space-y-2">
+              <h4 class="text-sm font-medium text-primary"><%= t("transactions.show.potential_duplicate_title") %></h4>
+              <p class="text-sm text-secondary"><%= t("transactions.show.potential_duplicate_description") %></p>
+
+              <div class="mt-3 p-3 rounded bg-container border border-primary">
+                <div class="flex items-center justify-between">
+                  <div>
+                    <p class="text-sm font-medium text-primary"><%= potential_match.name %></p>
+                    <p class="text-xs text-secondary"><%= potential_match.date.strftime("%b %d, %Y") %> • <%= potential_match.account.name %></p>
+                  </div>
+                  <p class="text-sm font-medium <%= potential_match.amount.negative? ? 'text-green-600' : 'text-primary' %>">
+                    <%= format_money(-potential_match.amount_money) %>
+                  </p>
+                </div>
+              </div>
+
+              <div class="flex items-center gap-2 mt-3">
+                <%= button_to t("transactions.show.merge_duplicate"),
+                    merge_duplicate_transaction_path(@entry.transaction),
+                    method: :post,
+                    class: "btn btn--primary btn--sm",
+                    data: { turbo_frame: "_top" } %>
+                <%= button_to t("transactions.show.keep_both"),
+                    dismiss_duplicate_transaction_path(@entry.transaction),
+                    method: :post,
+                    class: "btn btn--outline btn--sm",
+                    data: { turbo_frame: "_top" } %>
+              </div>
+            </div>
+          </div>
+        </div>
+      <% end %>
+    <% end %>
+
     <% dialog.with_section(title: t(".overview"), open: true) do %>
       <div class="pb-4">
         <%= styled_form_with model: @entry,