🐛 Bug Fix - Commit Message

  fix: resolve namespace isolation issue in rule import functionality

  The rule import process was incorrectly triggering REFRESH events for all namespaces
  instead of only the target namespace, causing cross-namespace event pollution.

  **Problem:**
  - When importing rules to namespace A, all namespaces (A, B, C...) received REFRESH events
  - This was caused by using `syncAll()` which broadcasts to all namespaces
  - Violated namespace isolation principle

  **Solution:**
  - Replace `syncAll()` with `syncAllByNamespaceId()` in import controller
  - Ensure only the target namespace receives REFRESH events
  - Maintain proper namespace isolation during rule import operations

  **Files Changed:**
  - shenyu-admin/src/main/java/com/woo/shenyu/admin/controller/ConfigsExportImportController.java

  **Testing:**
  - ✅ Import rules to namespace A - only namespace A receives events
  - ✅ Other namespaces (B, C) are unaffected
  - ✅ Namespace isolation is maintained

  📋 GitHub Issue Description

  # Bug Report: Cross-Namespace Event Pollution During Rule Import

  ## 🐛 **Bug Description**
  When importing rules to a specific namespace, the system incorrectly triggers REFRESH events for rules in ALL namespaces instead of only the target namespace.

  ## 🔍 **Root Cause Analysis**
  The issue is in `ConfigsExportImportController.java` line 146:
  ```java
  // Problem: broadcasts to ALL namespaces
  syncDataService.syncAll(DataEventTypeEnum.REFRESH);

  The syncAll() method:
  1. Fetches rules from ALL namespaces via ruleService.listAll()
  2. Groups by namespace and sends events to each namespace
  3. Causes namespace B to receive REFRESH events when importing to namespace A

  🔧 Fix Applied

  Replace the problematic call with namespace-specific synchronization:
  // Solution: only sync target namespace
  syncDataService.syncAllByNamespaceId(DataEventTypeEnum.REFRESH, namespace);

  📊 Impact

  - Before: Cross-namespace event pollution
  - After: Proper namespace isolation
  - Affected Component: Rule import functionality
  - Severity: Medium (violates namespace isolation)

  ✅ Testing

  - Import rules to namespace A - only A receives events
  - Namespace B and C clients remain unaffected
  - WebSocket event filtering works correctly
  - No performance impact on other namespaces

  📁 Files Modified

  - shenyu-admin/src/main/java/com/woo/shenyu/admin/controller/ConfigsExportImportController.java

  🏷️ Labels

  - bug
  - namespace
  - websocket
  - data-sync
  - isolation

  ## 🚀 **Pull Request Title**
  fix: resolve namespace isolation issue in rule import functionality