honour date facet bounds in xsd2inst samples

[pjfanning]

SampleXmlUtil.formatDate ignored min/max facets on every date type except dateTime, and didn't respect them properly on dateTime either.

Why

• The random seed is a full dateTime. It was compared against the bounds before setBuiltinTypeCode cut it down to the facet's type. For date, time, gYear, gYearMonth, gMonth, gMonthDay and gDay, compareToGDate therefore always returned 2 (incomparable). The min check (>= 0) never matched, so the min branch never ran, and the max check (<= 0) let everything through.
• When a reset did fire, it added or subtracted 1–8 hours from the random date, not from the bound. So minInclusive 2100-01-01T00:00:00Z produced values like 2014-01-05T11:16:42.000+00:00.
• The min/max checks also treated an incomparable result (2) inconsistently. The same issue in the validator's min checks is handled in fail min facets on incomparable date and duration values #132.

Fix

• Cut the seed down to the type and decide its timezone first.
• Check the seed against all four facets the way validation does, counting an incomparable result as out of range.
• If the seed misses, try the bound itself (which suits the inclusive facets), then the bound stepped inwards by the smallest unit the type shows (P1Y, P1M, P1D, then PT1H down to PT0.001S for the time types).
• For partial types (gDay, gMonthDay etc.), fill in the missing fields before doing the arithmetic, then drop them again.

This also replaces the eight near-identical per-type blocks with one facet lookup.

formatDuration clamps field by field and has similar issues, but this PR leaves it alone.

Tests
Xsd2InstTest.testDateSamplesSatisfyTheirBounds generates samples for 12 facet/type combinations and validates each one against its schema. On trunk it fails on the first case. With the fix it passes, and it also passed locally with 2000 iterations per case. ./gradlew test is green.

🤖 Generated with Claude Code