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-risk/modules/01-capabilities.html

@@ -25,7 +25,7 @@
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           <h3>模拟交易 FR-1</h3>
-          <p><code>POST /api/simulate/trade</code>：risk_demo 或客户本人可提交；走 trade_gateway → 适当性 → 规则引擎。</p>
+          <p><code>POST /api/simulate/trade</code>：risk_demo 或客户本人可提交；走 模拟写 Core 网关（trade_gateway.py） → 适当性 → 规则引擎（risk_engine.py）。</p>
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       </div>
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@@ -84,7 +84,7 @@
     <div class="screen animate-in">
       <div class="translation-block">
         <div class="translation-code">
-          <span class="translation-label">CODE · simulate.py 鉴权</span>
+          <span class="translation-label">CODE · 模拟交易入口（simulate.py）鉴权</span>
           <pre><code><span class="code-line"><span class="code-keyword">if not</span> (auth.has_role(<span class="code-string">"risk_demo"</span>)</span>
 <span class="code-line">        <span class="code-keyword">or</span> (auth.is_customer()</span>
 <span class="code-line">            <span class="code-keyword">and</span> auth.customer_id == req.customer_id)):</span>