The feed doesn't say "Empty" before its persona is known

On opening, the feed showed "Empty" until the session had been read and a persona chosen, then loaded: a flash of a
wrong answer on every start (and the end-to-end sign-in took it for a loaded feed). CascadingState says once the session
has been read (IsSessionLoaded), and until then a feed with no persona yet is loading; a login without any persona still
gets its empty feed. The persona-switch test waits for the sibling's home read with another token than the first
persona's, instead of any home read after the switch was asked for.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Pages/Index.razor

@@ -155,6 +155,7 @@
 	(double Latitude, double Longitude)? position;
 	string positionError;
 	string loadedPersonaId;
+	bool waitingForPersona;
 	FeedQuery lastQuery;
 	DateTime? lastPollAt;
 	TimeSpan? lastLoadTook;
@@ -183,9 +184,11 @@
 			return;
 		}
 
+		// (while the session is still being read the persona isn't known yet: the feed is loading, not empty)
 		if (CascadingState.PersonaId is null)
 		{
-			IsLoading = false;
+			waitingForPersona = !CascadingState.IsSessionLoaded;
+			IsLoading = waitingForPersona;
 			return;
 		}
 
@@ -219,11 +222,19 @@
 		return true;
 	}
 
-	// The persona changed (NavMenu's switcher): everything on the page belongs to the old one.
+	// The persona is known (the session was read after the page opened) or changed (NavMenu's switcher): everything on the
+	// page belongs to it.
 	protected override async Task OnParametersSetAsync()
 	{
-		if (CascadingState.PersonaId is null || CascadingState.PersonaId == loadedPersonaId || IsLoading && loadedPersonaId is null)
+		if (waitingForPersona && CascadingState.IsSessionLoaded && CascadingState.PersonaId is null)
+		{
+			waitingForPersona = false;
+			IsLoading = false;
 			return;
+		}
+		if (CascadingState.PersonaId is null || CascadingState.PersonaId == loadedPersonaId || IsLoading && loadedPersonaId is null && !waitingForPersona)
+			return;
+		waitingForPersona = false;
 		await Reload();
 	}