Fix adding select empty values for docs component

[carlosabadia]

Closes #1795

[greptile-apps]

Greptile Summary

This PR fixes empty-value handling in the documentation component's render_select function by filtering out empty strings ("") from Literal type arguments before selecting a default value and rendering select options.

Changes made:

• Filters out empty-string literal values when building the literal_values list for Union[Literal, Breakpoints] types
• Uses the first non-empty argument as the initial option for Literal types, with a fallback to the original first arg if all values are empty
• Excludes empty-string items from the rx.select dropdown item list

Issue found:

• The color_scheme popover grid (line ~190) still iterates over list(map(str, type_.__args__)) without filtering empty strings — the same fix applied to the rx.select branch was not applied here, so an empty swatch could still be rendered in the color picker grid

Confidence Score: 4/5

Safe to merge after fixing the missed empty-string filter in the color_scheme popover grid

The fix is correct and targeted, but the color_scheme popover was not updated with the same empty-string filter applied elsewhere, leaving a real rendering defect in that branch

pcweb/pages/docs/component.py — color_scheme popover color grid loop at line 190

Important Files Changed

Filename	Overview
pcweb/pages/docs/component.py	Filters empty strings from Literal type args in select/option rendering, but misses the same filter in the color_scheme popover grid loop

Comments Outside Diff (1)

1. pcweb/pages/docs/component.py, line 190 (link)

   Missing empty-string filter in color_scheme popover

   The same empty-string filtering applied to the rx.select dropdown at line 213 was not applied to the color_scheme popover grid. An empty string in type_.__args__ would still be rendered as a color swatch here, producing a broken/invisible tile in the color picker.

_{Reviews (1): Last reviewed commit: "Fxi select empty values" | Re-trigger Greptile}