feat(icons): refresh Kimi logo, K adapts to theme via currentColor

Replace the inline Kimi placeholder mark with the vendor's refreshed
logo. The K glyph uses `currentColor` so it follows the theme text color
(dark in light mode, white in dark mode), while the brand accent dot is
pinned to the new #1783FF. Align the metadata fallback color accordingly.

src/icons/extracted/metadata.ts

@@ -305,7 +305,7 @@ export const iconMetadata: Record<string, IconMetadata> = {
     displayName: "Kimi",
     category: "ai-provider",
     keywords: ["moonshot"],
-    defaultColor: "#6366F1",
+    defaultColor: "#1783FF",
   },
   meta: {
     name: "meta",