feat(cdm): add fill first row/column toggle for icon distribution

[nulltyto]

Summary

• Adds a Fill Top Row First / Fill Left Column First toggle to CDM bar options, controlling whether the first or last row gets filled completely when icons don't divide evenly across rows
• Pairs the new toggle with Show Tooltip on Hover (moved from its own standalone row) on a new DualRow
• Number of Rows label dynamically switches to Number of Columns when Vertical Orientation is enabled
• Clamps effective numRows after computing stride (numRows = ceil(count/stride)) to prevent empty row bugs
• Slider getValue/setValue clamped to ceil(spellCount/2) for sensible limits

Test plan

• Set a bar to 2+ rows with an uneven icon count (e.g., 7 icons, 2 rows) — verify default shows 3 top / 4 bottom
• Toggle Fill Top Row First on — verify it shows 4 top / 3 bottom with the partial row centered
• Toggle Vertical Orientation — verify label changes to Fill Left Column First and Number of Columns
• Toggle fills left column first in vertical mode
• Set rows to 1 — verify the fill toggle is disabled with tooltip
• Remove spells until count < stored numRows — verify no empty rows appear
• Verify preview matches live bar layout in all configurations