Improve vault returns and fees table

[miohtama]

Why

Present returns and investor-facing fees together so the net return is easier to interpret across standard periods.

Lessons learnt

Period data for 6M and 1Y is provided through period_results, while 1M, 3M, and lifetime values use the top-level vault fields.

Summary

• Replace the separate Returns and Fees cards with one responsive Returns and fees table.
• Show gross and net returns across 1M, 3M, 6M, 1Y, and lifetime.
• Include investor-facing fee rows and compact mobile labels.