Declare StructuredQueriesCore so SQLiteData links as a dynamic framework

[jonphillips]

Summary

SQLiteData's sources reference StructuredQueriesCore symbols directly, but the target declares only StructuredQueriesSQLite. That is fine for swift build / swift test, and it breaks as soon as the product is built as a dynamic framework — which Xcode does for every package product in the graph the moment a test bundle enters the build.

This revives #441, which was closed on the understanding that #467 had resolved it. #467 is in 1.6.6; we are on 1.6.6 (and reproduce identically against 1.8.1), and the failure is unchanged. I suspect that reporter's configuration differed — the manifest omission itself is still present on main today.

Answering the question from #441

Because StructuredQueriesSQLite re-exports those two libraries, so it should be sufficient to just depend on the one.

That holds for the compiler and not for the linker. @_exported import is a compile-time re-export: it makes the names visible to the type checker. It is not -reexport_framework, so StructuredQueriesSQLite.framework does not vend StructuredQueriesCore's symbols on SQLiteData.framework's behalf. When every product is a separate dylib, SQLiteData.framework's link line contains only its declared dependencies, and the direct references go unresolved.

A static build hides it completely, because every transitive archive is on the same link line anyway. That is why swift build, swift test, and a plain xcodebuild build are all green while build-for-testing fails — and, I suspect, why this has stayed latent.

Reproduction

No complex project needed. The trigger is simply a test bundle in an Xcode graph:

1. An Xcode project with an app target that depends on a local SwiftPM package.
2. That package depends on sqlite-data and defines any @Table type.
3. Add a unit-test bundle target to the project.
4. xcodebuild build-for-testing -scheme <App> -destination 'platform=iOS Simulator,...'

Step 3 is the whole trick: adding the test bundle flips every package product from static to dynamic. Without it the same project builds clean.

The failure

Undefined symbols for architecture arm64:
  "protocol conformance descriptor for Foundation.Data : StructuredQueriesCore.QueryBindable in StructuredQueriesCore",
      referenced from: ... in SQLiteData.o
  "(extension in StructuredQueriesCore):Foundation.Data.queryBinding.getter : StructuredQueriesCore.QueryBinding",
      referenced from: SQLiteData._SystemFieldsRepresentation.queryBinding.getter ... in SQLiteData.o
                       SQLiteData._AllFieldsRepresentation.queryBinding.getter ... in SQLiteData.o
  "protocol conformance descriptor for Foundation.UUID : StructuredQueriesCore.QueryRepresentable in StructuredQueriesCore", ...
ld: symbol(s) not found for architecture arm64
Ld .../PackageFrameworks/SQLiteData.framework/SQLiteData normal (in target 'SQLiteDatadynamic-product' from project 'sqlite-data')

Note the referencing objects are SQLiteData.o itself — _SystemFieldsRepresentation, _AllFieldsRepresentation, and the CKSyncEngine.PendingRecordZoneChange extension — so this is not a consumer reaching through SQLiteData for something; it is SQLiteData's own code needing a library it does not declare.

Verification

Applying this change to a local checkout makes SQLiteData.framework link, and build-for-testing then completes.

Environment: Xcode 27.0 beta / iOS 27 simulator SDK, sqlite-data 1.6.6 and 1.8.1, swift-structured-queries 0.31.3 and 0.34.0. Both version pairs fail identically and are fixed identically.

[jonphillips]

P.S. Love what you guys do.