2.1 - #2

paramui.py:771

• step is treated as a regex pattern for any non-empty string (except *.…/folder). This will misclassify sentinel strings like file/button as regex patterns (and even reject initial values that don't match). Consider excluding non-regex sentinel values from pattern registration.

This issue also appears in the following locations of the same file:

• line 809
• line 844
  paramui.py:846

• Headless initialization registers regex patterns for any non-empty string step (even when initial_value is not a string), and doesn't exclude sentinel values like file. This can cause unexpected validation behavior later. Align the condition with the UI path (string-valued + pattern-looking steps only).
  paramui.py:919
• The docstring says valid text becomes "green/default", but the implementation doesn’t set green and (after this PR) hardcodes black for valid text. Update the docstring to match the actual behavior (or change the behavior to truly restore the default color).

This issue also appears on line 983 of the same file.
paramui.py:986

• _apply_pattern_color hardcodes fg='black' for valid input, which doesn’t reliably restore the widget’s original/default foreground (and can be unreadable in dark themes). Prefer resetting to the default foreground instead of forcing black.
  paramui.py:813
• The new regex-textbox branch triggers for any non-empty string step. That means sentinel strings like file (or any other future string-based widget type) will be treated as regex validation. Make the regex branch conditional on successful pattern registration instead (e.g., variable in self.patterns).