fix(ui): unify the button size scale app-wide

[Gordex2014]

Closes #728.

Summary

• Establish one canonical ordinary-action scale across the UI: 30px height, 12px horizontal padding, 12px type, and 9px radius.
• Keep primary, danger, and current variants geometry-neutral; retire the duplicate accent variant.
• Normalize icon actions to a 30px square and remove page-specific button geometry from the query builder, resource editor, Batch, Bulk Import, tenants, and SQL workspaces.
• Document the component contract and make it executable through app-wide, dynamic-state, responsive, accessibility, and no-JavaScript coverage.

Reconciliation with main

• Reconciled onto main at 92c3762bf56caeed08715560be63eafd12a3d40b.
• Preserved the single Batch footer introduced by fix(ui): Batch/Transaction round 3 — single footer, error placement, focus, header count, tab icons #736: the geometry and busy-state coverage now targets the surviving top Cancel/Execute pair instead of restoring the removed footer.
• Retained the current Query Builder behavior from main while applying the shared scale.

Evidence

Both captures are from the final reconciled binary. Every visible .btn in these surfaces measured 30px high with 9px radius and 12px type. Emphasis changes color only.

Query Builder — icon, secondary, primary, and save actions	View Definitions — secondary, danger, primary, and save actions

Measured examples:

• Query Builder: Copy 30×30; Recent, Run, and Save all 30px high.
• View Definitions: Run, Duplicate, Delete, Create New, and Save all 30px high across neutral, danger, and primary variants.

Testing

• cargo fmt --all -- --check
• cargo test -p helios-ui
• npm run test:unit — 8 passed
• cargo build -p helios-hfs --features ui
• CI=1 HFS_E2E_BASE_URL=http://127.0.0.1:63528 npx playwright test — 270 passed, 7 expected configuration skips
• git diff --check

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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