[philliphoff]

Summary

.NET 8 reached end of support in November 2026, so the libraries (EncDotNet.Iso8211, EncDotNet.S57, EncDotNet.Noaa) now target net10.0 only. 0.10.0 is the last release that targets .NET 8; this lands in 0.11.0.

• Target frameworks: the three library projects drop their net8.0;net10.0 override and use net10.0 from the root Directory.Build.props.
• Package validation: the baseline (0.9.0) still ships a net8.0 build, so PackageValidationBaselineFrameworkToIgnore marks the drop as intentional (otherwise PKV006). Remove it once the baseline is 0.11.0 or later.
• Trimming: IsTrimmable no longer needs to be limited to the net10.0 build.
• CI: a new test-net11 job builds with the .NET 10 SDK, then runs the tests on the .NET 11 runtime (DOTNET_ROLL_FORWARD=LatestMajor, prereleases allowed). That's what consumers on .NET 11 run. Drop dotnet-quality: preview once .NET 11 is released.
• Docs: the READMEs, CONTRIBUTING, getting started, docs index, Copilot instructions and docs/versioning.md now say .NET 10. The versioning page also records the policy of dropping a .NET version when its support ends.

No net11.0 target yet: it only helps once the libraries use a .NET 11-only API, and adding a target framework later isn't a breaking change.

Standards alignment

• ISO/IEC 8211 (iso8211)
• S-57 records, topology, updates or exchange sets (s57-enc)
• Legacy chart viewer, maintenance only (chart-viewer)
• N/A: build, CI, docs or tooling only

Standard section references cited in code or docs: None.

Tests

• Added or updated xUnit tests under tests/
• Test input is built in memory; no real ENC cells are committed
• dotnet test --configuration Release passes locally

Not run locally: nuget.org was unreachable from the build machine. Restoring from the local package cache was enough to pack EncDotNet.Iso8211 and EncDotNet.S57, which passed package validation against 0.8.1 with the framework ignore in place (and failed with PKV006 without it). EncDotNet.Noaa, the viewer and the unit tests need packages that weren't cached, so CI is the first full run, including the new test-net11 job.

Documentation

• Updated the affected package's src/<project>/README.md
• Updated guides under docs/ if user-facing behavior changed
• New public APIs have XML doc comments
• docfx docfx.json --warningsAsErrors passes, if docs changed

Dependencies

• No new NuGet dependencies, OR versions added to
  Directory.Packages.props (not in the .csproj)
• gh-advisory-database security check run for any new dependency

Breaking changes

Dropping the net8.0 target from EncDotNet.Iso8211, EncDotNet.S57 and EncDotNet.Noaa: consumers on .NET 8 must stay on 0.10.0 or move to .NET 10. No API changes. EncDotNet.S100 is unaffected if it already targets .NET 10.