feat(app): redesign attachment cards (#35945)

Co-authored-by: Brendan Allan <git@brendonovich.dev>
Co-authored-by: Brendan Allan <14191578+Brendonovich@users.noreply.github.com>

packages/app/src/context/platform.tsx

@@ -37,6 +37,9 @@ type PlatformBase = {
   /** Open a local path in a local app (desktop only) */
   openPath?(path: string, app?: string): Promise<void>
 
+  /** Reveal a local path in the system file manager; false when the path does not exist (desktop only) */
+  revealPath?(path: string): Promise<boolean>
+
   /** Restart the app  */
   restart(): Promise<void>