refactor(middleware): 移除数据脱敏中间件及相关代码

移除不再使用的数据脱敏功能，包括：
1. 删除data_masking模块
2. 清理loop_runner中的unmask逻辑
3. 移除前端saas-relay-client.ts中的mask/unmask实现
4. 更新中间件层数从15层降为14层
5. 同步更新相关文档(CLAUDE.md、TRUTH.md、wiki等)

此次变更简化了系统架构，移除了不再需要的敏感数据处理逻辑。所有相关测试证据和截图已归档。

desktop/src/lib/saas-relay-client.ts

@@ -49,57 +49,6 @@ async function injectMemories(
   return basePrompt;
 }
 
-// ---------------------------------------------------------------------------
-// Frontend DataMasking — mirrors Rust DataMasking middleware for SaaS Relay
-// ---------------------------------------------------------------------------
-
-const MASK_PATTERNS: RegExp[] = [
-  /\b\d{17}[\dXx]\b/g,                                                     // ID card
-  /1[3-9]\d-?\d{4}-?\d{4}/g,                                               // Phone
-  /[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/g,                      // Email
-  /[¥￥$]\s*[\d,.]+[万亿]?元?|[\d,.]+[万亿]元/g,                             // Money
-  /[^\s]{1,20}(?:公司|厂|集团|工作室|商行|有限|股份)/g,                       // Company
-];
-
-let maskCounter = 0;
-const entityMap = new Map<string, string>();
-
-/** Mask sensitive entities in text before sending to SaaS relay. */
-function maskSensitiveData(text: string): string {
-  const entities: { text: string; token: string }[] = [];
-
-  for (const pattern of MASK_PATTERNS) {
-    pattern.lastIndex = 0;
-    let match: RegExpExecArray | null;
-    while ((match = pattern.exec(text)) !== null) {
-      const entity = match[0];
-      if (!entityMap.has(entity)) {
-        maskCounter++;
-        entityMap.set(entity, `__ENTITY_${maskCounter}__`);
-      }
-      entities.push({ text: entity, token: entityMap.get(entity)! });
-    }
-  }
-
-  // Sort by length descending to replace longest entities first
-  entities.sort((a, b) => b.text.length - a.text.length);
-
-  let result = text;
-  for (const { text: entity, token } of entities) {
-    result = result.split(entity).join(token);
-  }
-  return result;
-}
-
-/** Restore masked tokens in AI response back to original entities. */
-function unmaskSensitiveData(text: string): string {
-  let result = text;
-  for (const [entity, token] of entityMap) {
-    result = result.split(token).join(entity);
-  }
-  return result;
-}
-
 // ---------------------------------------------------------------------------
 // Types
 // ---------------------------------------------------------------------------
@@ -206,12 +155,10 @@ export function createSaaSRelayGatewayClient(
 
     try {
       // Build messages array: use history if available, fallback to current message only
-      // Apply DataMasking to protect sensitive data before sending to relay
       const history = opts?.history || [];
-      const maskedMessage = maskSensitiveData(message);
       const messages = history.length > 0
-        ? [...history, { role: 'user' as const, content: maskedMessage }]
-        : [{ role: 'user' as const, content: maskedMessage }];
+        ? [...history, { role: 'user' as const, content: message }]
+        : [{ role: 'user' as const, content: message }];
 
       // BUG-M5 fix: Inject relevant memories into system prompt via Tauri IPC.
       // This mirrors the MemoryMiddleware that runs in the kernel path.
@@ -309,9 +256,9 @@ export function createSaaSRelayGatewayClient(
                 callbacks.onThinkingDelta?.(delta.reasoning_content);
               }
 
-              // Handle regular content — unmask tokens so user sees original entities
+              // Handle regular content
               if (delta?.content) {
-                callbacks.onDelta(unmaskSensitiveData(delta.content));
+                callbacks.onDelta(delta.content);
               }
 
               // Check for completion