Visual validation feedback for invalid alias entries

[devoreofox]

Problem/Opportunity Space

Currently there is no visual feedback in the UI when an alias entry is invalid - for example if the name is blank, blacklisted, contains a space, or the command list is empty. Users have no way of knowing why an alias isn't working without inspecting it manually.

Acceptance Criteria

• Invalid alias entries are visually distinguished in the main window
• The specific reason for invalidity is communicated to the user
• Valid entries are not visually affected
• Validation state updates in real time as the user types

Suggested solution

Use ImGui's text colouring to highlight invalid fields in red or orange, and show a tooltip or inline message explaining the specific validation failure. Reference the error display pattern in the original SimpleTweaks CommandAlias code.

Suggested design

• Red/orange tint on the name input field when invalid
• Tooltip on hover explaining the specific issue (empty, blacklisted, contains space)
• Warning indicator in the enabled column when the entry is invalid regardless of enabled state
• Mirror the error message pattern from SimpleTweaks' DrawConfig method

Testing Considerations

Happy path

• Valid entries show no error styling
• Fixing an invalid entry immediately removes the error styling
• Tooltip correctly describes the specific validation failure

Sad path

• Blacklisted name shows appropriate error message
• Empty name field is flagged
• Name with a space is flagged
• Empty command list is flagged
• All error states are mutually exclusive and show the correct message