feat: 新增聊天页面和AI服务，支持文本、语音交互、流式响应和会话管理。

src/services/aiService.ts

@@ -95,6 +95,121 @@ export async function sendChatMessage(
   return data;
 }
 
+/**
+ * Send a chat message with streaming response
+ * Validates: Requirements 12.1, 12.5 (Streaming Upgrade)
+ */
+export async function streamChatMessage(
+  message: string,
+  existingSessionId: string | undefined,
+  onChunk: (text: string) => void
+): Promise<AIChatResponse> {
+  const sessionId = existingSessionId || getSessionId();
+  const token = localStorage.getItem('token'); // Assuming auth token is stored here
+
+  // Use fetch directly for streaming support
+  const response = await fetch(`${import.meta.env.VITE_API_URL}/ai/chat/stream`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      'Accept': 'text/event-stream',
+      'Authorization': `Bearer ${token}`,
+    },
+    body: JSON.stringify({
+      session_id: sessionId,
+      message,
+    }),
+  });
+
+  if (!response.ok || !response.body) {
+    throw new Error(`Failed to start stream: ${response.statusText}`);
+  }
+
+  return new Promise<AIChatResponse>(async (resolve, reject) => {
+    const reader = response.body!.getReader();
+    const decoder = new TextDecoder();
+    let buffer = '';
+
+    // State for SSE parsing
+    let currentEvent: string | null = null;
+    let finalResult: AIChatResponse | null = null;
+
+    try {
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+
+        const chunk = decoder.decode(value, { stream: true });
+        buffer += chunk;
+
+        const lines = buffer.split('\n');
+        buffer = lines.pop() || ''; // Keep incomplete line
+
+        for (const line of lines) {
+          const trimmed = line.trim();
+          if (trimmed === '') {
+            // End of event block
+            currentEvent = null;
+            continue;
+          }
+
+          if (trimmed.startsWith('event:')) {
+            currentEvent = trimmed.substring(6).trim();
+          } else if (trimmed.startsWith('data:')) {
+            const dataStr = trimmed.substring(5).trim();
+            if (!dataStr) continue;
+
+            if (currentEvent === 'message') {
+              try {
+                const data = JSON.parse(dataStr);
+                if (data.text) {
+                  onChunk(data.text);
+                }
+              } catch (e) {
+                // If not JSON, treat as raw text (fallback)
+                onChunk(dataStr);
+              }
+            } else if (currentEvent === 'result') {
+              try {
+                const data = JSON.parse(dataStr);
+                // Convert snake to camel
+                finalResult = toCamelCase(data) as unknown as AIChatResponse;
+                if (finalResult.sessionId) {
+                  currentSessionId = finalResult.sessionId;
+                }
+              } catch (e) {
+                console.error('Failed to parse result:', e);
+              }
+            } else if (currentEvent === 'error') {
+              try {
+                const errData = JSON.parse(dataStr);
+                reject(new Error(errData.error || 'Unknown stream error'));
+                return;
+              } catch (e) {
+                reject(new Error(dataStr));
+                return;
+              }
+            }
+          }
+        }
+      }
+
+      if (finalResult) {
+        resolve(finalResult);
+      } else {
+        // If we have no result but the stream finished safely,
+        // we might want to construct a minimal success response if we got messages.
+        // For now, let's treat it as a success if we got at least one message, or error otherwise.
+        // Actually, the result event is CRITICAL for session ID and confirmation cards.
+        reject(new Error("Stream ended without final result"));
+      }
+
+    } catch (err) {
+      reject(err);
+    }
+  });
+}
+
 /**
  * Transcribe audio to text
  * Validates: Requirements 12.2, 12.6
@@ -415,4 +530,5 @@ export default {
   formatConfirmationCard,
   getFinancialAdvice,
   getDailyInsight,
+  streamChatMessage,
 };