fix: compact todo-item spacing, fix checkbox alignment in detail

Todo items in preview were ~60px tall because marked.js wraps
checkbox-list content in <p> tags, and .prose p adds 0.75em
vertical margin inside the flex item. Three changes:

  - .todo-item p { margin:0; min-height:0 } kills the paragraph
    bloat inside todo rows.
  - Padding 5px→2px, min-height 28→24px, gap 10→8px for tighter
    stacking.
  - align-items switches from center to flex-start with margin-top
    on the checkbox so it sits at the first text line regardless of
    whether the <li> contains a bare text node or a <p>. Fixes the
    upward shift that appeared in the detail preview but not in the
    side panel.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

electron/package.json

@@ -1,6 +1,6 @@
 {
   "name": "hyprcrd",
-  "version": "1.9.23",
+  "version": "1.9.24",
   "description": "hyprcrd — self-hosted card manager",
   "main": "main.js",
   "scripts": {