fix: refresh knowledge items and don't show processing items on filtered files

[lucaseduoli]

This pull request improves the accuracy and responsiveness of the knowledge table in the search page, especially when handling file statuses and active filters. The changes ensure that the frontend reflects the backend's authoritative file status, avoids showing irrelevant task files when filters are applied, and keeps the UI updated as files are processed or removed.

Knowledge Table Row Handling:

• The buildKnowledgeTableRows function now accepts a hasActiveFilter parameter and, when a filter is active, only returns backend search results to prevent displaying task-only files that do not match the filter. [1] [2]
• Merging of file metadata has been improved so that the backend's status always takes precedence over the task file's status, ensuring the UI reflects the true ingestion state of each file.

Search Page Behavior:

• The search query now auto-refetches every 5 seconds to keep results up to date, and the loading state is more accurately tracked using isSearchLoading. [1] [2]
• The buildKnowledgeTableRows function is now called with the new hasActiveFilter parameter to support correct filtering behavior.

Task File State Synchronization:

• In the task context, when files disappear from a task (e.g., after being processed), their status is updated from "processing" to "active" and the search results are refreshed, ensuring the UI quickly reflects backend changes.

[Wallgau]

LGTM