fix: preserve queued wiki housekeeping tasks

[cctv549681]

Description

Fixes a false-positive housekeeping failure for wiki knowledge rows that are still waiting in the task queue.

This PR updates housekeeping to distinguish genuinely orphaned processing/finalizing knowledge rows from rows that are still backed by queued or active tasks. It also adds a precise pending-op lookup for wiki ingest tasks, so a finalizing wiki knowledge item is not marked failed while its durable pending operation still exists.

Changes include:

• Add read-only task queue inspection before housekeeping marks stale knowledge as failed
• Check task_pending_ops by exact wiki ingest dedup key for finalizing wiki rows
• Add a dedup index migration for task_pending_ops
• Add regression tests for queued task, wiki pending-op, and probe-error cases

Type of Change

• 🐛 Bug fix

Related Issue

Fixes #

Testing

go test ./internal/application/service -run 'TestHousekeeping'
go test ./internal/application/repository -run 'TestTaskPendingOps'

Checklist

• make fmt && make lint && make test pass locally
• Self-reviewed the code
• Added/updated tests covering the change
• Updated related documentation (README, docs/, Swagger annotations, etc.)
• Breaking changes are clearly called out in the description above

Screenshots / Recordings

before:

after: