fix(server-storage): keep duplicated tabs off live journals, drain writes around remove-all, normalize legacy Stalker rows on the move

- A page marks its unconfirmed-writes record closed on pagehide (not into
  the back-forward cache); a new page takes over the previous page load's
  saved writes only when that record is closed, stale or missing, so a
  duplicated tab, which copies sessionStorage, leaves the running tab its
  writes.
- PlaylistsService.removeAll lets queued playlist writes land first and
  makes writes issued meanwhile wait until it finished; the server store
  refuses a document without an id.
- Moving browser data sets the explicit Stalker portal-mode flag on rows
  from before it (withExplicitStalkerPortalFlag, now shared with
  PlaylistsService).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/shared/interfaces/src/lib/stalker-portal-mode.util.ts

@@ -26,6 +26,29 @@ export function isFullStalkerPortalUrl(url: string): boolean {
     return url.includes('/stalker_portal') || url.includes('/server/load.php');
 }
 
+/**
+ * A Stalker playlist saved before the explicit flag existed, with the flag
+ * set from its URL; any other playlist comes back unchanged.
+ */
+export function withExplicitStalkerPortalFlag<
+    T extends {
+        macAddress?: string;
+        isFullStalkerPortal?: boolean;
+        portalUrl?: string;
+        url?: string;
+    },
+>(playlist: T): T {
+    if (!playlist?.macAddress || playlist.isFullStalkerPortal !== undefined) {
+        return playlist;
+    }
+    return {
+        ...playlist,
+        isFullStalkerPortal: isFullStalkerPortalUrl(
+            playlist.portalUrl ?? playlist.url ?? ''
+        ),
+    };
+}
+
 /**
  * Whether a playlist should use the full-portal auth lifecycle
  * (handshake, Bearer token, watchdog).