Forward options through do_parse and its parser wrappers

[OskarEichler]

Summary

do_parse accepts an options hash but drops it when calling its parsers. Forward it consistently and let the duration/at wrappers accept optional options. This fixes multi-cron output, deterministic cron randomization and Chronic's reference time. It covers the raising API missed by the earlier non-raising fix in #116.

Reproduction

Run after require 'fugit':

require 'chronic'
p Fugit.do_parse('every day at 16:15 and 18:30', multi: true).map(&:to_cron_s)
# ["15 16 * * *", "30 18 * * *"]
p Fugit.do_parse('next weekday', now: Time.utc(1999, 12, 3)).strftime('%Y-%m-%d')
# "1999-12-06", rather than a date relative to today

Verification

• rbenv Ruby 4.0.6, TZ=UTC. Master baseline and this individual patch: 1,524 existing tests, 3,379 assertions, zero failures, one existing pending test.
• 8 focused checks for this change, run outside the repository. The combined release-based branch passes 1,517 existing RSpec examples, zero failures, one pending, plus 998 focused checks.
• Also checked the combined master changes with unmodified registry EtOrbi 1.4.1/Raabro 1.5.0: 1,524 tests/3,379 assertions, zero failures, one pending, and 997 focused checks. The extra blank-line check requires the independently fixed Raabro empty-input behavior; it is not claimed to pass on unmodified Raabro.
• Individual/release checks used the same versions of EtOrbi/Raabro with their separately proposed fixes. Syntax and whitespace checks pass. Combined source has the same 18 pre-existing Lint warnings, with no new warnings. Release gem packaging checked.

Compatibility and limitations

Supplied options now take effect, so multi:true can return an array and multi: :fail can raise as documented. Existing calls without options remain supported; do_parse_at/do_parse_duration gain an optional second argument.

No dependency/version upgrades, test additions or test modifications are included. The task's no-new-tests constraint was followed; reproduction/check scripts stayed outside the repository. Other Ruby versions and platforms await upstream CI. No production execution was performed. Prepared with Codex assistance.