fix: force text wrapping in table cells

[silverkszlo]

Closes #970

Fixes issue where long continuous text created infinitely wide cells instead of wrapping to multiple lines.

• Add max-width constraint to cells in generated images
• Override white-space: pre-wrap from nested divs with !important
• Apply word-break styles to all nested elements (div, p, span)

Before in edit dialog:

image:

After in edit dialog:

image:

[benjaminfrueh]

@silverkszlo there is one small issue. When the columns take up the full width, it becomes difficult to add text to the table head column of a new empty narrow column. The only way to focus this column is by clicking in the small space to the left of the three-dot menu or by using tab. Clicking directly in the table-head column places the cursor in the next row instead.