fix(ui): support inline custom answers for string choice fields in connect

[rekram1-node]

Web/desktop /connect, string field with options + custom: true:

 <AuthFormView>
-  <List>                         custom ignored, no way to type a value
-    GitHub.com
-    GitHub Enterprise
+  <RadioGroup>
+    ( ) GitHub.com
+    ( ) GitHub Enterprise
+    (•) Type your own answer
+        [ inline TextField ]
+  </RadioGroup>
+  [Continue]                     disabled until chosen or typed

TUI /connect, same field:

 selectAnswer
-  DialogSelect → "Type your own answer" → second DialogPrompt popup
+  StringChoiceField
+    1. GitHub.com
+    2. GitHub Enterprise
+    3. [inline editor]           esc → back to options