refactor: migrate all icons from Untitled UI to FontAwesome Pro Duotone

Replace all @untitledui/icons imports across 55 files with equivalent
@fortawesome/pro-duotone-svg-icons icons, using FontAwesomeIcon wrappers
(FC<{ className?: string }>) for prop-based usage and inline replacements
for direct JSX usage. Drops unsupported Untitled UI-specific props
(strokeWidth, numeric size). TypeScript compiles clean with no errors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/base/avatar/base-components/avatar-add-button.tsx

@@ -1,4 +1,5 @@
-import { Plus } from "@untitledui/icons";
+import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
+import { faPlus } from "@fortawesome/pro-duotone-svg-icons";
 import type { ButtonProps as AriaButtonProps } from "react-aria-components";
 import { Tooltip as AriaTooltip, TooltipTrigger as AriaTooltipTrigger } from "@/components/base/tooltip/tooltip";
 import { cx } from "@/utils/cx";
@@ -26,7 +27,7 @@ export const AvatarAddButton = ({ size, className, title = "Add user", ...props
                 className,
             )}
         >
-            <Plus className={cx("text-current transition-inherit-all", sizes[size].icon)} />
+            <FontAwesomeIcon icon={faPlus} className={cx("text-current transition-inherit-all", sizes[size].icon)} />
         </AriaTooltipTrigger>
     </AriaTooltip>
 );