Check-in [e9e08cbb58]

# Conflicts: # CHANGELOG.md check-in: 2a0701c7d3 user: [email protected] tags: feat/submanifest-reader, main, trunk

fossil's printf carries a %.17g value in C long double: a 64-bit double on macOS arm64 and Windows, 80-bit x87 on x86-64 Linux. The 16th digit, and so the event time fossil stores, differs between the two for about one time in five, which is why TestTextJulianDayMatchesFossilBinary passed on macOS and failed against CI's linux-x64 fossil. SQLite is not involved: julianday() counts integer milliseconds and 3.52.0's text-to-double conversion is integer arithmetic, neither using LONGDOUBLE_TYPE.

fossilPrintf17g now runs fossil's algorithm in a big.Float with the significand width of the platform's long double (53, 64 or 113 bits). Against all 4,007 times fossil stored in the failing CI run, 849 of them different from macOS fossil's, the 64-bit form matches every one; the 53-bit form still matches macOS fossil. The binary128 width (arm64 Linux) follows the same arithmetic but has not been compared with such a fossil. Times written on one platform and rebuilt by fossil on another may differ in the last place, as two fossils do. check-in: 387204fa55 user: [email protected] tags: feat/submanifest-reader, main, trunk