Split UI (#1245)

* Initial split transaction support

* Add support to unsplit and edit split

* Update show.html.erb

* FIX address reviews

* Improve UX

* Update show.html.erb

* Reviews

* Update edit.html.erb

* Add parent category to dialog

* Update en.yml

* Add UI indication to totals

* FIX ui update

* Add category select like rest of app

* Add split ui

* Add settings configuration for split transactions

- Adds a new settings section for appearance changes
- Also adds extra checks for delete and API calls
- Also adds checks for parent/child changes

* fixes

- split transactions dark mode fix
- add split transactions to context menu

* Update entry.rb

1. New validation split_child_date_matches_parent — prevents saving a split child with a date different from its parent. This is the root-cause fix that
   protects all flows at once.
  2. Bulk update guard — bulk_update! now strips :date from attributes when processing split children, preventing the validation from raising and silently
   skipping the date change instead.

* N+1 fix for split_parent?

* Update entry.rb

  Problem: In bulk_update!, when a split child has :date removed from attrs (line 432) and the remaining attrs is empty (e.g., the bulk update only
  changed the date), entry.update! {} still ran as a no-op. But lock_saved_attributes! and mark_user_modified! at lines 443-444 executed unconditionally,
  incorrectly marking untouched split children as user-modified and opting them out of future syncs.

  Fix:
  1. Added a changed flag to track whether any actual modification happened
  2. Wrapped entry.update! in an if attrs.present? check so no-op updates are skipped
  3. Gated lock_saved_attributes! and mark_user_modified! behind if changed, so they only run when the entry was actually modified (either via attribute
  update or tag update)

* fixes

1. Indentation in show.html.erb Settings section — The split button block and delete block had extra indentation making them appear nested inside guard
  blocks they weren't part of. Fixed to match actual nesting.
  2. Skip @split_parents query when grouping is off — The controller now only loads split parent entries when show_split_grouped? is true, saving a query
  with joins when the feature is disabled.

app/controllers/transactions_controller.rb

@@ -27,6 +27,30 @@ class TransactionsController < ApplicationController
 
     @pagy, @transactions = pagy(base_scope, limit: safe_per_page)
 
+    # Preload split parent data
+    entry_ids = @transactions.map { |t| t.entry.id }
+
+    # Load split parent entries for grouped display (only when grouping is enabled)
+    @split_parents = if Current.user.show_split_grouped?
+      split_parent_ids = @transactions.filter_map { |t| t.entry.parent_entry_id }.uniq
+      if split_parent_ids.any?
+        Entry.where(id: split_parent_ids)
+             .includes(:account, entryable: [ :category, :merchant ])
+             .index_by(&:id)
+      else
+        {}
+      end
+    else
+      {}
+    end
+
+    # Preload which entries on this page are split parents (have children) to avoid N+1
+    @split_parent_entry_ids = if entry_ids.any?
+      Entry.where(parent_entry_id: entry_ids).distinct.pluck(:parent_entry_id).to_set
+    else
+      Set.new
+    end
+
     # Load projected recurring transactions for next 10 days
     @projected_recurring = Current.family.recurring_transactions
                                   .active