fix(knowledge): use current parser rules for batch reparse

[Jonesxq]

Description

Batch reparse tasks without an explicit process_config reload each document's stored process overrides. Upload-time parser-engine snapshots then take precedence over the knowledge base's current parser rules, so changing the parser engine does not affect failed documents selected for batch reparse.

This change clears only the stored parser-engine rule snapshots before a nil-config batch reparse:

• both top-level and nested chunking_config parser rules are removed;
• document-specific chunking, multimodal, and parser options are preserved;
• explicit batch process_config and single-document reparse behavior are unchanged;
• metadata is updated only when a parser snapshot exists, and update errors flow through the existing batch outcome aggregation.

This is a focused implementation against the current main. It follows the backend direction discussed in the closed, unmerged #1901 and accounts for the nested snapshot identified there; #2094 explored a broader frontend-driven alternative.

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 💥 Breaking change
• 📚 Documentation update
• 🎨 Refactor
• ⚡ Performance improvement
• 🧪 Test
• 🔧 Configuration / Build / CI

Related Issue

Fixes #1892

Testing

go test ./internal/application/service -run 'TestClearStoredParserEngineRules|TestRunKnowledgeListReparseSubmissions|TestReparseKnowledgeManualEnqueueFailureIsVisible' -count=1
go vet ./internal/application/service
golangci-lint run --new-from-rev=origin/main ./internal/application/service

All focused commands pass; golangci-lint reports 0 issues.

go test ./internal/application/service -count=1 was also run. On Windows it fails only while removing SQLite temporary files in these existing tests:

• TestDataSourceServiceDeleteSQLiteCleansUpAfterSoftDelete
• TestDataSourceServiceDeleteKeepsCleanupStateWhenSoftDeleteFails
• TestDeleteKnowledgeBaseCleansUpSQLiteDataSources

The same weknora.db file-lock cleanup failures reproduce on an unchanged main worktree.

Checklist

• git diff --check origin/main...HEAD passes
• Changed source files are formatted
• Targeted tests for the changed package pass
• Diff-scoped lint passes for the changed package
• Unrelated full-package Windows failures are documented above and reproduced on main
• Self-reviewed the code
• Added tests covering top-level and nested snapshots, no-op behavior, preserved overrides, and update failures
• Documentation is not affected; no public API or configuration changed
• No breaking changes

Screenshots / Recordings

Not applicable; this is a backend batch-processing fix.

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.