Issue 32: Add ISO8601 timestamp to date display title attribute

Add ISO8601 (UTC) formatted timestamp as a native browser tooltip on all
date displays. This allows users to easily copy the exact timestamp while
still seeing human-readable relative times and formatted dates in the
custom tooltip.

Fixes #32

Author: WilliamZhang9

packages/web/src/app/[domain]/components/DisplayDate.tsx

@@ -1,24 +1,15 @@
 import { getFormattedDate } from "@/lib/utils"
 import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@/components/ui/tooltip"
 
-const formatFullDate = (date: Date) => {
-    return new Intl.DateTimeFormat("en-US", {
-        month: "long",
-        day: "numeric",
-        year: "numeric",
-        hour: "numeric",
-        minute: "2-digit",
-        second: "2-digit",
-        timeZoneName: "short",
-    }).format(date)
-}
-
 interface DisplayDateProps {
     date: Date
     className?: string
 }
 
 export const DisplayDate = ({ date, className }: DisplayDateProps) => {
+    // Format date in ISO8601 (UTC) format
+    const iso8601Date = date.toISOString()
+    
     return (
         <TooltipProvider>
             <Tooltip>
@@ -28,7 +19,7 @@ export const DisplayDate = ({ date, className }: DisplayDateProps) => {
                     </span>
                 </TooltipTrigger>
                 <TooltipContent>
-                    <p>{formatFullDate(date)}</p>
+                    <p>{iso8601Date}</p>
                 </TooltipContent>
             </Tooltip>
         </TooltipProvider>