feat(datagrid): show column type in header hover tooltip (#435)

[benedettoraviotta]

What

Adds a DataGrip-style tooltip on data-grid column headers: hovering a header shows <name>: <type> (e.g. id: uuid).

Closes #435

How

• The column data type is read from the already-available columnMetadata (data_type) via the existing columnTypeMap in DataGrid.tsx — no backend changes.
• The tooltip reuses the existing floating-surface look through the reserved-but-previously-unused --bg-tooltip theme token (bg-tooltip border border-strong rounded-lg shadow-xl), with the same group-hover fade used elsewhere.
• Positioned with absolute (not fixed) because the sticky <thead> carries a translateY transform, which would break fixed anchoring.
• pointer-events-none so it never intercepts header clicks/sort.
• The native sort-hint title is suppressed only while the type tooltip is shown, to avoid two overlapping tooltips on hover.

Scope

Shows whenever column metadata is present (table browse). Arbitrary query results carry no per-column type in QueryResult, so no tooltip is shown there — sort-hint title behavior is unchanged for those columns.

Verification

• pnpm typecheck — pass
• pnpm exec eslint src/components/ui/DataGrid.tsx — pass
• Verified visually via pnpm tauri dev (Postgres table browse).

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 file)

• src/components/ui/DataGrid.tsx — adds a DataGrip-style column type tooltip on header hover using the existing columnTypeMap. Tooltip is properly positioned with absolute inside the sticky header, uses the reserved --bg-tooltip theme token, and suppresses the native title sort hint to avoid overlap. The columnTypeMap dependency is correctly added to the useMemo array. No bugs, security issues, or breaking changes detected.

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_{Reviewed by kimi-k2.6-20260420 · Input: 87.1K · Output: 9.4K · Cached: 138.3K}

[debba]

Looks good!
Thanks for it :)