Improve edited video indicators and preserve publish date

- Update `VideoCard.js` to display "• Edited" instead of "(edited)" for better visual consistency.
- Update `app.js` to format the modal's "Last Edited" timestamp as "Last edited: [Absolute] ([Relative])".
- Ensure `EditModal.js` correctly backfills and preserves `published_at` to prevent date resets.
- Verify edit logic with existing tests.

js/app.js

@@ -8762,9 +8762,9 @@ class Application {
       (normalizedPostedAt === null || normalizedEditedAt - normalizedPostedAt >= 60);
 
     if (shouldShowEdited) {
-      payload.edited = `Last Edited: ${formatAbsoluteDateWithOrdinalUtil(
-        normalizedEditedAt
-      )}`;
+      const abs = formatAbsoluteDateWithOrdinalUtil(normalizedEditedAt);
+      const rel = this.formatTimeAgo(normalizedEditedAt);
+      payload.edited = `Last edited: ${abs} (${rel})`;
     }
 
     return payload;

js/ui/components/VideoCard.js

@@ -956,9 +956,15 @@ export class VideoCard {
       Number.isFinite(this.video?.created_at) &&
       this.video.created_at > this.postedAt + 60
     ) {
+      const separator = this.createElement("span", {
+        classNames: ["text-muted-strong", isCompact ? "" : "mx-1"],
+        textContent: "•",
+      });
+      separator.setAttribute("aria-hidden", "true");
+      metadata.appendChild(separator);
+
       const edited = this.createElement("span", {
-        classNames: ["ml-1"],
-        textContent: "(edited)",
+        textContent: "Edited",
       });
       metadata.appendChild(edited);
     }