Implements plan §13.19 sections for document browsing, query debugging,
and task monitoring in the Admin Web UI.
**Documents Section:**
- Paginated document browser per index with configurable limit/offset
- Filter builder with support for equals, notEquals, gt, gte, lt, lte, in, exists operators
- CSV/NDJSON import via drag-and-drop triggering §13.9 streaming import
- Export documents to JSON
- Dynamic table rendering based on document fields
**Query Sandbox Section:**
- Filter builder for constructing complex query filters
- Sort builder for multi-field sorting with asc/desc
- Facet-request builder for faceted search
- Instant-run with per-shard latency breakdown display
- One-click §13.20 explain integration (query plan visualization)
- Side-by-side diff vs. shadow (§13.16) for comparing live vs shadow results
**Tasks Section:**
- Active and recent tasks display with filtering by status, index, and type
- Per-node breakdown showing task distribution
- Retry/cancel functionality where applicable
- Pagination for large task lists
- Detailed task view modal with error information
**UI/UX Enhancements:**
- Consistent styling with existing admin sections
- Responsive design for mobile and desktop
- Loading states and error handling
- Progress indicators for long-running operations
Closes: miroir-uhj.19.3
041cb5a2a8