Fix egui layer ID panic on first run

This commit fixes a panic that occurred when the application was started
for the first time with no real accounts. The panic was:

"Widget 9AEC changed layer_id during the frame from LayerId { Background 9AEC }
to LayerId { Foreground 7E24 }"

Root cause:
- The previous implementation called route_to() during the Initializing state
- This happened during the first frame render, triggering navigation animations
- egui-nav attempted to render widgets on different layers during the transition
- This violated egui's requirement that widgets must stay on the same layer

Solution:
- Added a `need_account_redirect` flag to defer navigation until after first frame
- During initialization, we now set the flag instead of calling route_to()
- In the Initialized state, we check the flag and perform the navigation
- This ensures navigation happens after the first frame completes, avoiding layer conflicts

The fix resolves the crash while maintaining the desired behavior of automatically
redirecting users to the add account screen when no real accounts exist.

crates/notedeck_columns/src/app.rs

@@ -48,6 +48,9 @@ pub enum DamusState {
 pub struct Damus {
     state: DamusState,
 
+    /// Flag to defer account redirect until after first frame to avoid egui layer conflicts
+    need_account_redirect: bool,
+
     pub decks_cache: DecksCache,
     pub channels_cache: crate::channels::ChannelsCache,
     pub relay_config: crate::relay_config::RelayConfig,
@@ -261,21 +264,28 @@ fn update_damus(damus: &mut Damus, app_ctx: &mut AppContext<'_>, ctx: &egui::Con
             }
 
             // Check if we only have the default fallback account (no real accounts)
-            // If so, redirect to add account screen on first run
+            // If so, set flag to redirect on next frame (to avoid egui layer ID conflicts)
             let selected_account = app_ctx.accounts.get_selected_account();
             let account_count = app_ctx.accounts.cache.into_iter().count();
             if selected_account.key.pubkey == notedeck::FALLBACK_PUBKEY() &&
                selected_account.key.secret_key.is_none() &&
                account_count == 1 {
-                // Only have the fallback account, redirect to add account
-                info!("No real accounts found, redirecting to add account screen");
+                // Only have the fallback account, set flag to redirect after first frame
+                info!("No real accounts found, will redirect to add account screen");
+                damus.need_account_redirect = true;
+            }
+        }
+
+        DamusState::Initialized => {
+            // Perform deferred account redirect if needed
+            if damus.need_account_redirect {
+                damus.need_account_redirect = false;
+                info!("Performing deferred redirect to add account screen");
                 damus.columns_mut(app_ctx.i18n, app_ctx.accounts)
                     .get_selected_router()
                     .route_to(Route::add_account());
             }
         }
-
-        DamusState::Initialized => (),
     };
 
     if let Err(err) = try_process_event(damus, app_ctx, ctx) {
@@ -763,6 +773,7 @@ impl Damus {
             timeline_cache,
             drafts: Drafts::default(),
             state: DamusState::Initializing,
+            need_account_redirect: false,
             note_options,
             options,
             //frame_history: FrameHistory::default(),
@@ -820,6 +831,7 @@ impl Damus {
             timeline_cache: TimelineCache::default(),
             drafts: Drafts::default(),
             state: DamusState::Initializing,
+            need_account_redirect: false,
             note_options: NoteOptions::default(),
             //frame_history: FrameHistory::default(),
             view_state: ViewState::default(),