Split native packaging into a package family + Cake Frosting build

[sergey-v9]

Split native packaging into a package family + Cake Frosting build

Summary

Restructures the LadybugDB .NET binding's packaging so the native engine no longer ships inside the
managed package. Instead it's a package family:

• LadybugDB — managed-only (no native payload).
• LadybugDB.Native.<rid> — one package per platform, carrying just that RID's native library.
• LadybugDB.Native — meta-package that depends on all per-RID packages.

Consumers reference LadybugDB plus a native package: the meta-package for "runs anywhere", or a
single LadybugDB.Native.<rid> for a slim, single-platform app. All packaging is driven by a new
Cake Frosting build project under cake/.

Motivation

The old single package bundled every platform's native library into one .nupkg, so every consumer
carried all of them regardless of target. Splitting the natives into per-RID packages (with a meta
"all platforms" package) lets an app pull only what it needs, while keeping a one-line install for the
common case.

What changed

Package family

• Managed LadybugDB is now managed-only: removed the runtimes/** native glob from
  nuget/nuget-package.props (it now ships lib/net10.0 + lib/netstandard2.0 + README + symbols only).
• Each LadybugDB.Native.<rid> carries runtimes/<rid>/native/* plus an empty lib/netstandard2.0/_._
  marker (so NuGet adds no compile reference) and declares no dependencies.
• LadybugDB.Native meta-package depends on all five per-RID packages.
• Shipped RIDs: win-x64, linux-x64, linux-arm64, osx-x64, osx-arm64.
• The managed package intentionally has no dependency on any native package — that decoupling is
  what makes the slim, single-RID install possible.

Build pipeline (cake/)

• A Cake Frosting console app: LadybugDB.Build.csproj + BuildContext.cs (which also hosts the Main
  entry point), and the pipeline tasks under Tasks/ (Pipeline.cs for the small tasks +
  VerifyPackagesTask.cs). Bootstrap with build.ps1 / build.sh.
• Tasks: Clean, Restore, BuildManaged, Test, FetchNatives, PackManaged, PackRuntimes,
  PackNativeMeta, VerifyPackages, Pack, Default.
• BuildContext is the single source of truth for the RID set and the RID -> (release asset, library)
  mapping. EnsureNativeStaged reuses a locally-built native if present, otherwise downloads the pinned
  engine release asset (via gh) and extracts the canonical library (pulling the real shared object out
  of the .so/.dylib symlink chain, since NuGet doesn't preserve symlinks).
• Per-RID packages come from one parameterized template (cake/native/LadybugDB.Native.Runtime.csproj,
  packed once per RID). The meta-package is a nuspec template (cake/native/LadybugDB.Native.nuspec)
  with version/commit substituted at pack time. All packing is dotnet-only (no nuget.exe / mono).
• VerifyPackages asserts the managed assemblies, every per-RID payload, and the meta's dependency set,
  so a silent packaging regression fails the build instead of shipping a broken package.

Versioning

• The package version tracks the upstream engine version, with an -alpha.N prerelease suffix while in
  development. Current default: 0.17.0-alpha.1.
• It lives in ONE place - version.txt at the binding root - read by BuildContext, the managed
  nuget-package.props, and both CI workflows. Bump the alpha (or the engine) there with no code change.
  --prerelease "" cuts a stable build equal to the engine version; --package-version <v> overrides
  exactly (the release workflow passes the v* git tag).

CI / release

• ci.yml and release.yml now invoke the pipeline (dotnet run --project cake/... -- --target ...)
  instead of inline shell. ci.yml runs a test matrix (linux-x64 + win-x64) and a pack smoke;
  release.yml runs the linux-x64 test gate, packs + verifies, then publishes all packages via OIDC.

Docs

• README (install + build sections), AGENTS.md (Packaging).

Consumption

# runs on any supported platform
dotnet add package LadybugDB
dotnet add package LadybugDB.Native

# slim, single-platform
dotnet add package LadybugDB
dotnet add package LadybugDB.Native.win-x64

Validation

• Local end-to-end (win-x64 host, engine v0.17.0): --target Pack produced and verified all 7
  packages as 0.17.0-alpha.1 (correct layouts; meta pins all five per-RID deps; no stray references);
  --target Test passed 28/28 with the native loaded (no skips).
• Build is warning- and lint-clean.

Next steps / TODO

Maintainer actions before first publish:

• Owner — still TODO (one-time): create the release GitHub environment on
  LadybugDB/ladybug-dotnet and add secret NUGET_USER = the nuget.org profile name (NOT email).
  The publish job declares environment: release and NuGet/login@v1 reads secrets.NUGET_USER, so
  without these the publish step fails with a 403/auth error.
• First green CI run: trigger release.yml via workflow_dispatch to confirm the linux-x64 gate +
  all-RID download/pack on CI (proven locally on win-x64 so far).

Follow-ups (can land later):

• Bump the -alpha.N suffix as the binding stabilizes; drop it for the first stable v0.17.0.
• Phase 3 (remaining): expand the suite to mirror the Java + C API tests over dataset/tinysnb.
• Phase 5 (optional): Native AOT validation, Arrow C Data interface, observability.

[sergey-v9]

@adsharma 🙌 When you get a moment, could you also review the TODO section - we have to setup an environment here in the repo settings.

[adsharma]

This is the same format used by nodejs: https://www.npmjs.com/search?q=ladybugdb%2Fcore

What are the benefits of keeping LadybugDB and LadybugDB.Native separate?

[adsharma]

Can you leave the environment blank for now? We can add it back when we have a release vs test environment.

create the release GitHub environment on
LadybugDB/ladybug-dotnet and add secret NUGET_USER = the nuget.org profile name (NOT email).

Done