Force refresh and sort modes

[mathiasbourgoin]

Context

Add manual refresh and sorting options for the key list.

Force refresh (r)

• Immediately re-fetch balances and delegation data for the selected key (or all visible keys)
• Show spinner during fetch
• Update detail panel when done

Sort modes (s)

• Cycle through sort orders: by alias (A-Z), by balance (high→low), by network
• Current sort mode indicated in the header
• Persists within session (resets on page re-entry)

Files

• src/ui/pages/keys_page.ml

Depends on

• Issue: Split-panel layout for keys page