#5093 "Shared format filters and status_class driven by Settings → Thresholds".
- steward/core/formatting.py: human_bytes (binary units), human_rate,
human_duration (two largest units), ago (a <time> titled with the absolute
UTC time) and status_class(value, kind, thresholds) -> ok/warn/crit/unknown,
which raises on a kind the thresholds don't name.
- app.py registers them as the bytes, rate, duration and ago filters and the
status_class global; threshold_style is now graded by status_class (and caps
its weight at 500).
- Replaces the copies: docker's _human_bytes/_human_uptime, core alerts'
_duration, the host-agent fmt_bps/fmt_bytes macros, the Traefik and UniFi
byte-rate arithmetic, the swarm-failures ago macro and two uptime spans.
- Tests: a table per helper, and every template compiled against the app's
filters, so an unknown filter fails CI rather than a page.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
