fix: show in-app chat deletion confirmation (#20)

* fix: make chat session deletion server controlled

* fix: show in-app chat deletion confirmation

frontend/src/app/globals.css

@@ -707,3 +707,6 @@ input:disabled, select:disabled { color: var(--color-ink-tertiary); background:
   .auth-panel h1 { font-size: var(--type-display-sm); }
   .admin-section { padding: var(--space-5); }
 }
+.session-delete-confirmation { position: fixed; inset: auto var(--space-5) var(--space-5) auto; z-index: 100; width: min(360px, calc(100vw - var(--space-10))); padding: var(--space-5); border: 1px solid var(--border); border-radius: 8px; background: var(--background); box-shadow: 0 12px 32px rgb(0 0 0 / 18%); }
+.session-delete-confirmation p { margin: 0 0 var(--space-4); }
+.session-delete-confirmation div { display: flex; justify-content: flex-end; gap: var(--space-3); }

frontend/src/app/page.tsx

@@ -695,6 +695,7 @@ export default function Home() {
   const [archivedSessionIds, setArchivedSessionIds] = useState<string[]>([]);
   const [showArchivedSessions, setShowArchivedSessions] = useState(false);
   const [sessionMenuId, setSessionMenuId] = useState<string | null>(null);
+  const [pendingSessionDeletion, setPendingSessionDeletion] = useState<ChatSession | null>(null);
   const [modelCatalog, setModelCatalog] = useState<PublicLanguageModelCatalog | null>(null);
   const [activeSessionId, setActiveSessionId] = useState("");
   const [draft, setDraft] = useState("");
@@ -1245,7 +1246,7 @@ export default function Home() {
   }
 
   async function deleteSession(session: ChatSession) {
-    if (!account || !window.confirm(`删除“${session.title}”？此操作不可恢复。`)) return;
+    if (!account) return;
     const previousSessions = sessions;
     const nextSessions = sessions.filter((item) => item.id !== session.id);
     setSessions(nextSessions);
@@ -2308,7 +2309,7 @@ export default function Home() {
             onToggleArchived: toggleArchivedSession,
             onDelete: (sessionId) => {
               const session = sessions.find((candidate) => candidate.id === sessionId);
-              if (session) void deleteSession(session);
+              if (session) setPendingSessionDeletion(session);
             },
           }}
           onAccountMenuOpenChange={setAccountMenuOpen}
@@ -2318,6 +2319,19 @@ export default function Home() {
           onOpenRedeem={() => openAccountDialog("redeem")}
           onOpenLogout={() => openAccountDialog("logout")}
         />
+        {pendingSessionDeletion ? (
+          <div className="session-delete-confirmation" role="alertdialog" aria-modal="true" aria-label="确认删除聊天记录">
+            <p>删除“{pendingSessionDeletion.title}”？此操作不可恢复。</p>
+            <div>
+              <button type="button" onClick={() => setPendingSessionDeletion(null)}>取消</button>
+              <button className="danger-button" type="button" onClick={() => {
+                const session = pendingSessionDeletion;
+                setPendingSessionDeletion(null);
+                void deleteSession(session);
+              }}>确认删除</button>
+            </div>
+          </div>
+        ) : null}
         <SidebarInset className="chat-panel" inert={activeAccountDialog !== null}>
           <header className="chat-header">
             <SidebarTrigger placement="inset" />

tests/test_session_management_entrypoints.py

@@ -13,6 +13,8 @@ def test_chat_history_management_actions_are_exposed() -> None:
     for expected in (
         "renameSession",
         "deleteSession",
+        "pendingSessionDeletion",
+        "确认删除",
         "togglePinnedSession",
         "toggleArchivedSession",
         "showArchivedSessions",