feat(threshold): Implement customer loss threshold configuration and notification system

- Added `ThresholdRepository` for managing customer loss threshold configurations and notifications.
- Introduced `threshold_service` to handle loss threshold alerts based on customer portfolio performance.
- Enhanced `customer_prompts` to include new intent for querying product net values.
- Updated `customer_service` to integrate new threshold alert functionality into existing workflows.
- Implemented `sanitize_postprocess` for improved compliance handling in customer interactions.
- Enhanced course documentation to reflect updates in advisor training modules and interactive elements.

This update significantly improves the customer experience by providing proactive loss threshold notifications and enhancing the overall service framework.

docs/course/jinrong-module-frontend/modules/02-chat-auth.html

@@ -30,14 +30,14 @@
         {"highlight":"flow-actor-1","label":"ChatPanel(agentType=advisor, mode=stream)"},
         {"highlight":"flow-actor-2","label":"useChatPanel → listChatSessions(token, advisor)","packet":true,"from":"1","to":"2"},
         {"highlight":"flow-actor-3","label":"chat.ts：Bearer + X-Agent-Type: advisor","packet":true,"from":"2","to":"3"},
-        {"highlight":"flow-actor-4","label":"chat.py：get_auth_context + 准入矩阵","packet":true,"from":"3","to":"4"},
+        {"highlight":"flow-actor-4","label":"对话 HTTP 入口（chat.py）：get_auth_context + 准入矩阵","packet":true,"from":"3","to":"4"},
         {"highlight":"flow-actor-1","label":"SSE 流式 delta → UI 逐字显示","packet":true,"from":"4","to":"1"}
       ]'>
         <div class="flow-actors">
           <div class="flow-actor" id="flow-actor-1"><span class="flow-actor-icon">💬</span><span>ChatPanel</span></div>
           <div class="flow-actor" id="flow-actor-2"><span class="flow-actor-icon">🪝</span><span>useChatPanel</span></div>
           <div class="flow-actor" id="flow-actor-3"><span class="flow-actor-icon">📡</span><span>api/chat.ts</span></div>
-          <div class="flow-actor" id="flow-actor-4"><span class="flow-actor-icon">🚪</span><span>chat.py</span></div>
+          <div class="flow-actor" id="flow-actor-4"><span class="flow-actor-icon">🚪</span><span>对话 HTTP 入口（chat.py）</span></div>
         </div>
         <p class="flow-step-label">对比：问数走 analyst.ts，无 X-Agent-Type</p>
         <div class="flow-controls">