fix: force basic line editor in init tests for CI compatibility

Thor prefers Readline when available, which reads from the real terminal
fd instead of $stdin. In CI there's no terminal, so Readline returns nil.
Stub Readline.available? to false so Thor falls back to Basic editor
which reads from $stdin (the StringIO in tests).

Author: dpaluy

test/cli/init_test.rb

@@ -78,8 +78,10 @@ def run_init(dir, input)
     out = nil
     Dir.stub(:pwd, dir) do
       Fizzy::Auth.stub(:token_data, TOKEN_DATA) do
-        $stdin = StringIO.new(input)
-        out, = capture_io { Fizzy::CLI.start(["init"]) }
+        Thor::LineEditor::Readline.stub(:available?, false) do
+          $stdin = StringIO.new(input)
+          out, = capture_io { Fizzy::CLI.start(["init"]) }
+        end
       end
     end
     out