Remove session controller actions other than delete

and do some general cleanup around sessions controllers and the
sign_in_as test helper

test/controllers/sessions/launchpad_controller_test.rb

@@ -6,14 +6,16 @@ class Sessions::LaunchpadControllerTest < ActionDispatch::IntegrationTest
 
     assert_response :success
 
-    assert_equal cookies[:_fizzy_launchpad_sig], "test-sig"
+    assert_select "form input#sig" do |node|
+      assert_equal node.length, 1
+      assert_equal node.first["value"], "test-sig"
+    end
   end
 
   test "create establishes a session when the sig is valid" do
     user = users(:david)
-    cookies[:_fizzy_launchpad_sig] = user.signal_user.perishable_signature
 
-    put session_launchpad_path
+    put session_launchpad_path(params: { sig: user.signal_user.perishable_signature })
 
     assert_redirected_to root_url
     assert parsed_cookies.signed[:session_token]
@@ -21,9 +23,8 @@ class Sessions::LaunchpadControllerTest < ActionDispatch::IntegrationTest
 
   test "returns 401 when the sig is invalid" do
     user = users(:david)
-    cookies[:sig] = "not-valid"
 
-    put session_launchpad_path
+    put session_launchpad_path(params: { sig: "invalid" })
 
     assert_response :unauthorized
   end

test/controllers/sessions_controller_test.rb

@@ -1,38 +1,10 @@
 require "test_helper"
 
 class SessionsControllerTest < ActionDispatch::IntegrationTest
-  ALLOWED_BROWSER    = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Safari/605.1.15"
-  DISALLOWED_BROWSER = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/114.0"
-
-  test "new" do
-    get new_session_path
-    assert_response :success
-  end
-
-  test "new enforces browser compatibility" do
-    get new_session_path, env: { "HTTP_USER_AGENT" => DISALLOWED_BROWSER }
-    assert_select "svg", message: /Your browser is not supported/
-
-    get new_session_path, env: { "HTTP_USER_AGENT" => ALLOWED_BROWSER }
-    assert_select "svg", text: /Your browser is not supported/, count: 0
-  end
-
-  test "create with valid credentials" do
-    post session_path, params: { email_address: "david@37signals.com", password: "secret123456" }
-    assert_redirected_to root_path
-    assert cookies[:session_token].present?
-  end
-
-  test "create with invalid credentials" do
-    post session_path, params: { email_address: "david@37signals.com", password: "wrong" }
-    assert_redirected_to new_session_path
-    assert_not cookies[:session_token].present?
-  end
-
   test "destroy" do
     sign_in_as :kevin
     delete session_path
-    assert_redirected_to new_session_path
+    assert_redirected_to Launchpad.login_url
     assert_not cookies[:session_token].present?
   end
 end