feat: Add disk usage display for projects (#2702)

[Harikrishnan1367709]

Add disk usage display for projects (#2702)

Adds a disk usage indicator to project cards in the projects overview,
showing how much storage space each project consumes.

Implementation:

• Created disk usage calculation utility that aggregates sizes from all
  Docker volumes (applications, databases, compose) across project environments
• Updated project API to include diskUsageBytes field
• Added formatted disk usage display with hard drive icon in project cards
• Optimized volume size queries by batching requests per server

Features:

• Shows total disk usage combining all volumes used by project services
• Formats sizes automatically (B → KB → MB → GB → TB)
• Handles remote servers correctly (respects serverId per service)
• Displays even when usage is 0 B

Fixes #2702