[BUGFIX] fix cellSettings not applied when table column filters are active

[rajusem]

Summary

Fixes cellSettings conditional formatting (e.g., showing "N/A" for null values) not being applied when column filters are active in the Table panel.

Root cause

cellConfigs was computed by iterating the unfiltered data array and keyed by array index (${index}_${columnKey}). The <Table> component receives filteredData which has different indices after filtering. This caused cellSettings overrides (text, colors) to either not appear or apply to incorrect cells when a filter was active.

Fix

Moved columnFilters state and filteredData memo before the cellConfigs memo, then changed cellConfigs to iterate filteredData instead of data. This ensures cellConfig indices always match the rows the Table renders.

All hooks remain unconditional (early returns are after all hook calls), so React Rules of Hooks are preserved. Sorting is unaffected — TanStack Table preserves row.id from the original data index through getSortedRowModel, so cellConfigs[cell.id] resolves correctly regardless of sort order.

How to reproduce (before fix)

1. Create a Table panel with multiple queries where some queries return data for a namespace and others don't (e.g., a multi-metric quota table)
2. Add cellSettings with a Misc/null condition (text: "N/A")
3. Enable filtering
4. Verify N/A appears correctly in the unfiltered view
5. Apply a column filter to show only a row with null values
6. Bug: N/A text disappears — cells show blank instead

Tests added

• N/A renders correctly for null values in unfiltered multi-query table
• N/A persists after filtering to a row with missing data (regression test)
• Genuine zero values are NOT replaced with N/A (false positive prevention)

Uses ARIA role-based selectors per UI guidelines.

Screenshots

Without filter :

With filter :

Checklist

• Pull request has a descriptive title and context useful to a reviewer.
• Pull request title follows the [<catalog_entry>] <commit message> naming convention using one of the
  following catalog_entry values: FEATURE, ENHANCEMENT, BUGFIX, BREAKINGCHANGE, DOC,IGNORE.
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