feat(goals): gate Goals v2 behind beta features toggle

Add require_beta_features! to GoalsController and GoalPledgesController,
hide the Goals nav item for non-beta users, and tag index/show headers
with the Beta pill marker. Update controller tests to enable the
preference in setup and assert the redirect for users without access.

test/controllers/goal_pledges_controller_test.rb

@@ -2,13 +2,24 @@ require "test_helper"
 
 class GoalPledgesControllerTest < ActionDispatch::IntegrationTest
   setup do
-    sign_in users(:family_admin)
+    @user = users(:family_admin)
+    @user.update!(preferences: (@user.preferences || {}).merge("beta_features_enabled" => true))
+    sign_in @user
     @goal = goals(:vacation_italy)
     @account = accounts(:depository)
     @pledge = goal_pledges(:open_transfer)
     ensure_tailwind_build
   end
 
+  test "redirects users without beta access" do
+    @user.update!(preferences: (@user.preferences || {}).merge("beta_features_enabled" => false))
+
+    get new_goal_pledge_url(@goal), headers: { "Turbo-Frame" => "modal" }
+
+    assert_redirected_to root_path
+    assert_match(/beta/i, flash[:alert])
+  end
+
   test "new renders the pledge form inside a turbo frame" do
     get new_goal_pledge_url(@goal), headers: { "Turbo-Frame" => "modal" }
     assert_response :success

test/controllers/goals_controller_test.rb

@@ -2,13 +2,24 @@ require "test_helper"
 
 class GoalsControllerTest < ActionDispatch::IntegrationTest
   setup do
-    sign_in users(:family_admin)
+    @user = users(:family_admin)
+    @user.update!(preferences: (@user.preferences || {}).merge("beta_features_enabled" => true))
+    sign_in @user
     @goal = goals(:vacation_italy)
     @depository = accounts(:depository)
     @connected = accounts(:connected)
     ensure_tailwind_build
   end
 
+  test "redirects users without beta access" do
+    @user.update!(preferences: (@user.preferences || {}).merge("beta_features_enabled" => false))
+
+    get goals_url
+
+    assert_redirected_to root_path
+    assert_match(/beta/i, flash[:alert])
+  end
+
   test "index renders with active filter by default" do
     get goals_url
     assert_response :success