Fix CI: improve security fix and add link checker configuration

- Fix import order (ast before asyncio)
- Remove NameError from exception handling (ast.literal_eval doesn't raise it)
- Add .lycheeignore to exclude intermittently unavailable star-history API
- Update link-check workflow to exclude star-history API and accept 503 status codes

.github/workflows/link-check.yml

@@ -14,6 +14,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: lycheeverse/lychee-action@v2
         with:
-          args: --no-progress --insecure --user-agent 'curl/7.68.0' README.md docs/ apps/ examples/ benchmarks/
+          args: --no-progress --insecure --user-agent 'curl/7.68.0' --exclude '.*api\.star-history\.com.*' --accept 200,201,202,203,204,205,206,207,208,226,300,301,302,303,304,305,306,307,308,503 README.md docs/ apps/ examples/ benchmarks/
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.lycheeignore

@@ -0,0 +1,5 @@
+# Exclude star-history API from link checking
+# This service is intermittently unavailable (503 errors)
+# but the link still works when the service is up
+.*api\.star-history\.com.*
+

apps/slack_data/slack_mcp_reader.py

@@ -7,10 +7,10 @@ for indexing in LEANN. It supports various Slack MCP server implementations and
 flexible message processing options.
 """
 
+import ast
 import asyncio
 import json
 import logging
-import ast
 from typing import Any, Optional
 
 logger = logging.getLogger(__name__)
@@ -148,7 +148,7 @@ class SlackMCPReader:
                     if match:
                         try:
                             error_dict = ast.literal_eval(match.group(1))
-                        except (ValueError, SyntaxError, NameError):
+                        except (ValueError, SyntaxError):
                             pass
                     else:
                         # Try alternative format
@@ -156,7 +156,7 @@ class SlackMCPReader:
                         if match:
                             try:
                                 error_dict = ast.literal_eval(match.group(1))
-                            except (ValueError, SyntaxError, NameError):
+                            except (ValueError, SyntaxError):
                                 pass
 
                 if self._is_cache_sync_error(error_dict):