Report Radix as 10, since the type is base 10

[matt-edmondson]

Fixes #116

What changed

• PreciseNumber.Radix now returns 10 instead of 2. The constant is renamed from BinaryRadix to DecimalRadix.
• TestRadix now expects 10. It pinned the wrong value before.

PreciseNumber stores significand × 10^exponent and does all of its digit work in base 10, which is also what decimal reports. Generic math code that reads T.Radix, for example to compute ulps or to decide whether scaling is exact, was treating the type as binary.

Behaviour change: this changes a public static value, and the commit subject carries that into the generated changelog.

Verification

• TestRadix fails with the fix reverted (Assert.AreEqual(10, PreciseNumber.Radix)) and passes with it.
• The full dotnet test suite passes: 385/385.

🤖 Generated with Claude Code

https://claude.ai/code/session_01M4xENzmZT4DZE8d5Hu6kEN

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Generated by Claude Code

[matt-edmondson]

Analyze & Release failed on 0ca4ab3, and the cause is outside this PR. SonarCloud's scanner could not create the analysis because https://api.sonarcloud.io/analysis/analyses returned Error 504 … "Endpoint request timed out". The build and tests in that job, and the Test jobs on ubuntu, macOS and windows, all passed. The diff doesn't touch the Sonar setup, and there is no fix to port on our side. I've re-run the failed job once.

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Generated by Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud