sessionItem calls nowSeconds() twice in ternary, can produce negative remaining_secs

[Sertug17]

In src/commands/sessions.ts line 672-673, nowSeconds() is called twice within the same ternary expression without caching:

remaining_secs:
    record.grace_ready_at > nowSeconds() ? record.grace_ready_at - nowSeconds() : 0,

If the system clock ticks between the two calls (e.g., first returns 999, second returns 1001), the guard passes but the subtraction produces a negative value (-1).

The correct pattern is already used elsewhere in the same file closeOneSession (line 338) caches now:

const now = nowSeconds();

Suggested fix:

const now = nowSeconds();
// ...
remaining_secs: record.grace_ready_at > now ? record.grace_ready_at - now : 0,