filter_breaks_to_range cannot filter temporal breaks, so out-of-domain ticks survive

[thomasp85]

This issue was surfaced during the Hephaestus writer work

Summary

filter_breaks_to_range (src/plot/scale/breaks.rs:292) returns the break list unchanged unless both range endpoints are ArrayElement::Number, and inside the predicate it explicitly keeps any break that is not a Number. A Date / DateTime / Time scale therefore never gets filtered: a calendar-aligned major computed outside the resolved domain survives, and both writers place a tick off-panel.

Reproduction

VISUALISE Date AS x, Temp AS y FROM ggsql:airquality
DRAW line
SCALE x SETTING breaks => '2 months'

domain: ['1973-04-23', '1973-10-07']
values: ['1973-04-01', '1973-06-01', '1973-08-01', '1973-10-01', '1973-12-01']

1973-04-01 and 1973-12-01 are both outside the resolved domain.

Suggested fix

Filter on ArrayElement::to_f64() for the range endpoints and the breaks alike — which is exactly what the minor breaks path already does — falling back to the current pass-through only when a value has no numeric projection.