Summary

This PR improves the dashboard UI/UX with a more structured layout.

What changed

• refined the main dashboard shell and content spacing
• improved header context and mobile navigation behavior
• reworked sidebar information architecture
• upgraded server selector styling and hierarchy
• added shared dashboard page header and empty state components
• applied the new header or empty state patterns across key dashboard routes:
  • Members
  • Moderation
  • Conversations
  • Tickets
  • Audit Log
• improved the Members and Tickets content areas to feel more clearly structured

Notes

This is a first pass dashboard UX overhaul focused on structure, consistency, and reducing clutter.
More polish and deeper visual work can follow in a later PR.

Validation

• ran targeted Biome checks on updated dashboard files
• did not run the full web test suite