fix(datagrid): restore spoken labels and minimums on structure grids

[datlechin]

Why

Follow-ups to #3406. Moving Triggers and ClickHouse Parts onto the data grid made VoiceOver read the Enabled and Active columns as YES or NO, and dropped the old per-column minimum widths. The DynamoDB maintenance preview, an API call with a JSON body, was highlighted as SQL, and the filter preview ignored the connection's engine.

Change

• Triggers and Parts speak Enabled or Disabled, Active or Inactive. The grid gains a per-cell spoken-text hook; every other grid reads what it drew before.
• A grid column can carry its own minimum width (30 pt stays the default). Triggers and Parts get their old minimums back.
• The DynamoDB maintenance preview is highlighted as JSON. The filter preview highlights with the connection's engine.

Verified

New tests read the cells through the accessibility API, apply the minimums through the column pool, and check the preview language per engine.