Allow timeline window/range, not just most recent

[CaptainStarbuck]

The --minutes option goes back N minutes. Allow:

• from-date
• to-date
• from-time
• to-time
• from-minutes
• to-minutes

When there is a range and the range ends in the past, or the last entry is within the range, the refresh won't show anything new. Refresh should indicate that there are no new transactions, but that it's still refreshing.

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I dunno if this is the best implementation. Opinions anyone?

[CaptainStarbuck]

v1.2.2-alpha-.1 is now available for use and commentary in the filter1 branch

Examples from the README:

$ node src/codex-usage.js \
    --from-date 2026-05-13T19:00:00 \
    --to-date 2026-05-13T21:00:00 \
    --scope sessions \
    --in-scope \
    --max-events 1900
Codex token usage from May 13, 7:00:00 PM to May 13, 9:00:00 PM

$ node src/codex-usage.js --from-date 5/1 --to-date 5/6
Codex token usage from May 1, 12:00:00 AM to May 6, 12:00:00 AM // beginning of day

The options are extensive and to me seem cumbersome, but if we want extensive filtering we need to express our wants somewhere, so here it is in CLI (and .env).