Add NumericRestrictionNode to the KQL PEG grammar so that range
operators work with numeric values, not just DateTimes. This enables
queries like `size>=1048576`, `photo.iso>=100`, `photo.fNumber>=2.8`,
and `photo.focalLength<50`.
Changes:
- ast: add NumericNode with Key, Operator, Value (float64)
- kql/dictionary.peg: add NumericRestrictionNode and Number rules
- kql/factory.go: add buildNumericNode()
- kql/cast.go: add toFloat64()
- bleve/compiler.go: compile NumericNode to NumericRangeQuery
Fixes: #12093
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
4b7349037f