Fix dark theme description text invisible on task detail page

Problem

On /tasks/<task-id> page in dark theme, the description text is invisible because text color matches background.

Light theme (correct):

• background: #f9fafb (light gray)
• color: #374151 (dark gray text)

Dark theme (broken):

• background: #374151 (dark gray)
• color: #374151 (inherited, same as background = invisible)

Fix

In Omni/Jr/Web/Style.hs, line ~1259, change:

".description" ? backgroundColor "#374151"

To:

".description" ? do
  backgroundColor "#374151"
  color "#e5e7eb"

Testing

1. Run jr web 2. Navigate to any task detail page (/tasks/t-xxx) 3. Toggle to dark theme (or use system dark mode) 4. Verify description text is visible (light gray on dark gray background)