Improve TUI readability and navigation feedback

[StefanBethge]

Current pain points:

• Long project/task labels were previously truncated too aggressively.
• The selected cell was highlighted, but the active row was not obvious enough.
• Overall grid readability can still be improved for dense weekly views.

Proposed scope:

• Improve wrapping behavior for long labels in the timesheet grid.
• Highlight the full selected row while keeping the active cell distinct.
• Review spacing, alignment, and visual hierarchy in the weekly grid and overlays.
• Keep the layout usable on smaller terminal widths.

Acceptance criteria:

• Long labels are wrapped instead of being cut off unnecessarily.
• The currently selected row is clearly visible.
• The active cell remains distinguishable within the selected row.
• The grid remains readable across common terminal widths.