## Summary
Move queue job history into a dedicated sidebar tab (gated by `Comfy.Queue.QPOV2`) and remove mixed job-history UI from the Assets sidebar so assets and job controls are separated.
## Changes
- **What**:
- Added `JobHistorySidebarTab` with reusable job UI primitives: `JobFilterTabs`, `JobFilterActions`, `JobAssetsList`, and shared `JobHistoryActionsMenu`.
- Added reactive `job-history` tab registration in `sidebarTabStore`; prepends above Assets when `Comfy.Queue.QPOV2` is enabled and unregisters cleanly when disabled.
- Added debounced search to `useJobList` (filters by job title, metadata, and prompt id).
- Extracted clear-history dialog logic to `useQueueClearHistoryDialog` and reused it from queue overlay and job history tab.
- Removed active-job rendering and queue-clear controls from assets list/grid/tab views; assets sidebar now focuses on media assets only.
- Removed the QPOV2 gate from `MediaAssetViewModeToggle` and updated queue/job localized copy.
- Added and updated tests for queue overlay header actions, job filters, search filtering, sidebar tab registration, and assets sidebar behavior.
## Review Focus
- Verify QPOV2 toggle behavior:
- `Docked Job History` menu action toggles `Comfy.Queue.QPOV2`.
- `job-history` tab insertion/removal order and active-tab reset on removal.
- Verify behavior split between tabs:
- Job controls (cancel/delete/view/filter/search/clear history/clear queue) live in Job History.
- Assets sidebar loading/empty states and list/grid rendering remain correct after removing active jobs.
## Screenshots (if applicable)
<img width="670" height="707" alt="image" src="https://github.com/user-attachments/assets/3a201fcb-d104-4e95-b5fe-49c4006a30a5" />
