cmd: compile packages from direct exports

docs/build-system.md

@@ -2802,15 +2802,28 @@ the final component of its import path; two logical identities for one physical
 directory are rejected rather than compiled twice.
 
 Packages compile serially in dependency-first postorder. The compiler emits the
-existing deterministic `.wwi` interface for every importable package and only
-exported declarations enter that interface. A source qualifier is visible only
-when its owning package directly imports it; private members and transitive-only
-qualifiers are compiler errors. For compatibility with public signatures that
-name deeper types, composed compiler units still carry transitive interface type
-facts for internal resolution, but those facts do not create source-visible
-bare names, package qualifiers, or value bindings. Replacing that
-source-like closure with a self-contained typed export encoding remains part of
-the later export-format work, not package-loader semantics.
+existing deterministic `.wwi` interface for every importable package. Its
+primary section contains that package's byte-sorted direct imports and exported
+declarations. The compiler then appends byte-sorted, origin-tagged sections for
+only the exported foreign type and constant facts recursively reachable from
+the primary public signatures. This makes each direct dependency interface
+self-contained for the public type information its consumers need while
+retaining the deeper declarations' original package identity. Checked fixed
+array dimensions are emitted as numeric type facts, so a public layout never
+requires exposing the private constant spelling that produced its length.
+
+A package compilation unit contains one `.wwi` for each byte-sorted **direct**
+import and no separately injected transitive interface. Origin-tagged facts
+inside those direct artifacts are compiler data, not source imports: a source
+qualifier is visible only when its owning package directly imports it, and
+private members, transitive-only qualifiers, bare values, and bare types remain
+compiler errors. In `-c` package mode the compiler coalesces repeated exported
+type/constant facts with the same origin, kind, and name, preserving one nominal
+type identity across diamonds; raw non-package `w6c` retains its existing
+duplicate behavior. The source-like `.wwi` syntax remains a transitional export
+encoding pending the binary `.wwe` format described above, but the direct-input
+ownership boundary is now live in production Cstage and WWstage compilers and
+drivers.
 
 An ordinary root is linked with the full reachable object closure into the
 requested executable (legacy WW programs may use a package name other than
@@ -2821,7 +2834,10 @@ identity (`ww build -p -I ROOT -o bar.a foo.bar` emits `foo.bar.*` symbols),
 while a literal directory uses its declared leaf package. Package output
 requires a directory and `-p` cannot be combined with assembly-only `-S`. Two
 cold builds with identical inputs are required to produce byte-identical
-requested products.
+requested products. Compiler intrinsics keep their package-mode runtime ABI
+independent of transitive source interfaces (for example, `alloc` lowers to the
+runtime allocator without requiring an `rt.wwi` compiler input), while the
+linker still receives every reachable package archive plus the runtime archive.
 
 ## 12. Candidate architectures and hard-gate decision