Family sharing (#1272)

* Initial account sharing changes

* Update schema.rb

* Update schema.rb

* Change sharing UI to modal

* UX fixes and sharing controls

* Scope include in finances better

* Update totals.rb

* Update totals.rb

* Scope reports to finance account scope

* Update impersonation_sessions_controller_test.rb

* Review fixes

* Update schema.rb

* Update show.html.erb

* FIX db validation

* Refine edit permissions

* Review items

* Review

* Review

* Add application level helper

* Critical review

* Address remaining review items

* Fix modals

* more scoping

* linter

* small UI fix

* Fix: Sync broadcasts push unscoped balance sheet to all users

* Update sync_complete_event.rb

 The fix removes the sidebar broadcasts (which rendered unscoped account groups using family.balance_sheet without user context)
  along with the now-unused sidebar_targets, account_group, and family_balance_sheet private methods.

  The sidebar will still update correctly — when the sync completes, Family::SyncCompleteEvent#broadcast fires family.broadcast_refresh, which triggers a
  morph-based page refresh for each user with their own authenticated session, rendering properly scoped sidebar content.

app/controllers/application_controller.rb

@@ -81,4 +81,14 @@ class ApplicationController < ActionController::Base
     def show_demo_warning?
       demo_host_match?
     end
+
+    def accessible_accounts
+      Current.accessible_accounts
+    end
+    helper_method :accessible_accounts
+
+    def finance_accounts
+      Current.finance_accounts
+    end
+    helper_method :finance_accounts
 end