fix(dashboard): drop the border around the footer folder toggle

The status-bar folder-toggle button had a 1px border + radius that made it
look like a chip. Per request, render it as a bare icon — transparent
background, no border. Hover now only shifts the icon color, the active
state drops to color only, and focus-visible still draws a focus ring with
border-radius applied so it remains a clean halo.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/dashboard/app/components/ProviderIcon.tsx

@@ -204,6 +204,7 @@ const providerConfig: Record<
   zai: { component: ZaiIcon, color: "#1A6DFF" }, // blue
   kimi: { component: KimiIcon, color: "#6C5CE7" }, // purple
   moonshot: { component: KimiIcon, color: "#6C5CE7" }, // purple (same as kimi)
+  "kimi-coding": { component: KimiIcon, color: "#6C5CE7", label: "Kimi" }, // purple (Kimi alias)
 };
 
 export function ProviderIcon({ provider, size = "sm" }: ProviderIconProps) {