feat(search): add similar sessions UI in FlowPilot sidebar

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

frontend/src/api/aiSessions.ts

@@ -11,6 +11,7 @@ import type {
   AISessionSummary,
   AISessionDetail,
   AISessionSearchResult,
+  SimilarSession,
   PickupSessionRequest,
 } from '@/types/ai-session'
 
@@ -122,6 +123,13 @@ export const aiSessionsApi = {
     })
     return response.data
   },
+
+  async getSimilar(sessionId: string, limit: number = 5): Promise<SimilarSession[]> {
+    const response = await apiClient.get<SimilarSession[]>(`/ai-sessions/${sessionId}/similar`, {
+      params: { limit },
+    })
+    return response.data
+  },
 }
 
 export default aiSessionsApi