fix: ghost session cleanup, new chat switching, and markdown overflow handling (#287)

src/stores/chat.ts

@@ -99,6 +99,7 @@ interface ChatState {
   switchSession: (key: string) => void;
   newSession: () => void;
   deleteSession: (key: string) => Promise<void>;
+  cleanupEmptySession: () => void;
   loadHistory: (quiet?: boolean) => Promise<void>;
   sendMessage: (text: string, attachments?: Array<{ fileName: string; mimeType: string; fileSize: number; stagedPath: string; preview: string | null }>) => Promise<void>;
   abortRun: () => Promise<void>;
@@ -973,8 +974,11 @@ export const useChatStore = create<ChatState>((set, get) => ({
           }
         }
         if (!dedupedSessions.find((s) => s.key === nextSessionKey) && dedupedSessions.length > 0) {
-          // Current session not found at all — switch to the first available session
-          nextSessionKey = dedupedSessions[0].key;
+          // Current session not found in the backend list
+          const isNewEmptySession = get().messages.length === 0;
+          if (!isNewEmptySession) {
+            nextSessionKey = dedupedSessions[0].key;
+          }
         }
 
         const sessionsWithCurrent = !dedupedSessions.find((s) => s.key === nextSessionKey) && nextSessionKey
@@ -1153,6 +1157,27 @@ export const useChatStore = create<ChatState>((set, get) => ({
     }));
   },
 
+  // ── Cleanup empty session on navigate away ──
+
+  cleanupEmptySession: () => {
+    const { currentSessionKey, messages } = get();
+    // Only remove non-main sessions that were never used (no messages sent).
+    // This mirrors the "leavingEmpty" logic in switchSession so that creating
+    // a new session and immediately navigating away doesn't leave a ghost entry
+    // in the sidebar.
+    const isEmptyNonMain = !currentSessionKey.endsWith(':main') && messages.length === 0;
+    if (!isEmptyNonMain) return;
+    set((s) => ({
+      sessions: s.sessions.filter((sess) => sess.key !== currentSessionKey),
+      sessionLabels: Object.fromEntries(
+        Object.entries(s.sessionLabels).filter(([k]) => k !== currentSessionKey),
+      ),
+      sessionLastActivity: Object.fromEntries(
+        Object.entries(s.sessionLastActivity).filter(([k]) => k !== currentSessionKey),
+      ),
+    }));
+  },
+
   // ── Load chat history ──
 
   loadHistory: async (quiet = false) => {