fix: Correct CJK/emoji orientation in collapsed columns (#1098)

[BradGroux]

Problem

When a column (lane) is collapsed horizontally, CJK characters and emoji in the title appear upside-down. Latin characters display correctly because they have no inherent orientation in vertical writing mode, but CJK and emoji glyphs get flipped by the per-element rotate(180deg).

Screenshots from #1098:

• Chinese characters: upside-down
• Emoji: rotated incorrectly relative to the title text

Root Cause

The collapsed column styling used:

.kanban-plugin__lane-header-wrapper {
  writing-mode: vertical-lr;
}
.kanban-plugin__lane-title-count,
.kanban-plugin__lane-title-text {
  transform: rotate(180deg);
}

This was a workaround for sideways-lr (not widely supported). The problem is that rotate(180deg) on individual text elements flips CJK/emoji glyphs upside-down since these characters have inherent orientation in vertical writing modes.

Fix

Moved the rotation to the wrapper level and switched writing mode:

.kanban-plugin__lane-header-wrapper {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}

vertical-rl + rotate(180deg) on the wrapper achieves the same bottom-to-top reading direction for Latin text while preserving correct glyph orientation for CJK characters and emoji — no per-element rotation needed.

Testing

• Latin text: reads bottom-to-top ✅ (same as before)
• CJK characters: correct orientation ✅
• Emoji: correct orientation ✅
• Lane title count badge: correct orientation ✅

Fixes #1098