[CmdPal] Allow custom width configuration for Dock extension widgets and Details panels

Description of the new feature / enhancement

Expected Behavior

As an extension developer creating custom extensions for the new Command Palette (CmdPal) Dock, I would like the ability to programmatically request or configure a custom width for both the minimized Dock band item and the expanded Details pane/panel.

Currently, the SDK enforces strict fixed widths. If an extension outputs dynamic or long strings, the text is immediately truncated with an ellipsis.

Ideally, the SDK should expose a way to:

1. Define a custom Width property (in pixels or columns) for a Dock widget.
2. Provide a flexible or dynamic sizing option (e.g., DetailSize.ExtraWide or a custom absolute pixel width) for the details panel so that content-heavy extensions aren't artificially constrained by the default layout dimensions.

Scenario when this would be used?

Scenario & Workflow Impact

I am currently coding a custom extension designed to display live-synced song lyrics in the Command Palette Dock as music plays.

Because lyrics vary wildly in length, single lines of text are constantly truncated by the rigid container size of the Dock. This completely breaks the readability and usefulness of the widget.

This layout restriction applies to many other data-dense, real-time tracking use cases as well (e.g., streaming logs, long file paths, system process arguments, or detailed network monitoring strings). Without a way to expand or customize the width, developers are forced to resort to hacky solutions like CPU-intensive ticker-tape text animations, which degrade the native, smooth look and feel of PowerToys.

Supporting information

Additional Context

• The issue is especially prominent in text-heavy or streaming-data extensions where text wrapping ruins the layout or truncation hides critical information.
• Adding layout flexibilities like an adjustable width parameter in the UI model/SDK components would greatly improve developer adoption of the new CmdPal extension ecosystem.

Review the CmdPal Dock widget and Details panel SDK APIs, focusing on where fixed widths and text truncation are enforced. Compare the requested custom width and flexible sizing options, then define and test a supported sizing contract for both minimized and expanded views using the lyrics scenario as acceptance criteria.