feat: add streamDocumentation SSE client for ticket notes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/aiSessions.ts

@@ -99,6 +99,69 @@ export const aiSessionsApi = {
     return response.data
   },
 
+  async streamDocumentation(
+    sessionId: string,
+    onChunk: (text: string) => void,
+    onDone: () => void,
+    onError: (error: string) => void,
+  ): Promise<void> {
+    const token = localStorage.getItem('access_token')
+    const baseUrl = import.meta.env.VITE_API_URL || ''
+
+    try {
+      const response = await fetch(
+        `${baseUrl}/api/ai-sessions/${sessionId}/documentation/stream`,
+        {
+          headers: {
+            Authorization: `Bearer ${token}`,
+          },
+        },
+      )
+
+      if (!response.ok) {
+        onError(`HTTP ${response.status}`)
+        return
+      }
+
+      const reader = response.body?.getReader()
+      if (!reader) {
+        onError('No response body')
+        return
+      }
+
+      const decoder = new TextDecoder()
+      let buffer = ''
+
+      while (true) {
+        const { done, value } = await reader.read()
+        if (done) break
+
+        buffer += decoder.decode(value, { stream: true })
+        const lines = buffer.split('\n')
+        buffer = lines.pop() || ''
+
+        for (const line of lines) {
+          if (line.startsWith('data: ')) {
+            const data = line.slice(6)
+            if (data === '[DONE]') {
+              onDone()
+              return
+            }
+            if (data.startsWith('[ERROR]')) {
+              onError(data.slice(8))
+              return
+            }
+            onChunk(data)
+          }
+        }
+      }
+      // Stream ended without [DONE]
+      onDone()
+    } catch (err) {
+      onError(err instanceof Error ? err.message : 'Stream failed')
+    }
+  },
+
   async rateSession(sessionId: string, data: { rating: number; feedback?: string }): Promise<void> {
     await apiClient.post(`/ai-sessions/${sessionId}/rate`, data)
   },