Round instead of truncate when formatting a duration from hours

[jtauschl]

Summary

Fixes OP-19969.

format_duration_from_hours passed its computed seconds value straight into Duration.new(seconds: ...), whose hash-based constructor (in the ruby-duration gem) truncates via Float#to_i rather than rounding -- e.g. 5.501 hours (19803.6 seconds) silently serialized as "PT5H30M3S" instead of the correctly rounded "PT5H30M4S", losing up to just under a second of precision on any value with a fractional-second remainder. This affects every caller of this shared formatter (work packages, meetings, time entries), not just time entries.

Change

Round the seconds value explicitly before constructing the Duration.

Test plan

• Updated the existing spec assertion that encoded the old truncating behavior as expected
• Verified live against a real 17.7.1 instance, both server-side and through the full REST API: before the fix, format_duration_from_hours(5.501) → "PT5H30M3S"; after the fix → "PT5H30M4S", and POST /api/v3/time_entries with hours: "PT5H30M3.6S" correctly returns "hours":"PT5H30M4S"

[github-actions]

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[jtauschl]

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