KSP: skip root-package declarations with a warning (#319) - #325

Closes #319

• Cause: Kotlin cannot refer to a root-package declaration from a named package, and every generated fragment and table is in one. qualifiedName.substringBeforeLast('.') also returned the function's own name as its 'package', so the generated call was unqualified and the consumer's compile failed.
• Fix: FragmentScanner skips root-package functions, properties and classes. KSP warns with the declaration's name and the remedy (add a package). Nothing that worked before changes, since the build previously failed.
• Test: the app fixture gains RootPackageDeclarations.kt (no package). RootPackageSkipTest checks that neither declaration is in the table. With the old scanner the fixture does not compile (red). With the fix, ksp fixtures:app desktopTest passes 80/80, the two warnings are printed, and the app's androidNative compile passes.