fix: improve WCAG compliance and mobile editor height

- Add aria-describedby to password inputs for screen readers
- Connect hint text to input via id reference
- Increase mobile editor min-height to 50vh

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/main.css

@@ -989,11 +989,11 @@ input:checked + .toggle-slider::before {
 	}
 
 	.editor-section {
-		min-height: 200px;
+		min-height: 50vh;
 	}
 
 	.editor-content {
-		min-height: 150px;
+		min-height: 40vh;
 	}
 
 	.preview-wrapper {