feat: Add skeleton loading states for document list and editor

[Ashvin-KS]

Problem

When loading documents or switching between documents, users see a blank screen or spinner. This feels slow and unprofessional.

Proposed Solution

Add skeleton loading states for:

• Document list on dashboard
• Document editor content area
• Sidebar navigation

Benefits

• Better perceived performance
• Smoother user experience
• Reduces layout shift

Implementation Notes

• Use CSS skeleton animations
• Match the layout of the actual content
• Show skeletons while data is fetching

[sanudking]

Hey! This looks like a great issue to work on. I'm a first-year CSE student at NIT Jalandhar participating in GSSoC 2026. I have knowledge in Typescript and would like to take this up. Can I get assigned? I'll submit a PR within a day or two. 🙏