[TrueFurina]

Summary

floor() and ceil() pass their argument straight to math.floor / math.ceil, which raise uncatchable OverflowError / ValueError on Infinity and NaN. Python's json.loads accepts those literals by default, so JSON data loaded the usual way can contain them and reach these functions:

>>> import json, jmespath
>>> jmespath.search('floor(@)', json.loads('Infinity'))
OverflowError: cannot convert float infinity to integer
>>> jmespath.search('ceil(@)', json.loads('NaN'))
ValueError: cannot convert float NaN to integer

Every other bad function argument in jmespath raises JMESPathTypeError, so code that does try: search(...) except JMESPathError: around a query cannot catch these.

Fix

Guard the two functions with math.isfinite() and raise JMESPathTypeError for non-finite inputs, matching the project's existing convention for invalid function arguments. Finite values are unaffected.

Verification

• Added tests/test_functions.py::test_floor_ceil_reject_non_finite (covers floor/ceil on Infinity/NaN) and test_floor_ceil_still_work_for_finite.
• Full suite: 993 passed, 1 skipped (baseline 991 passed).

Closes #381.