Fix tests for tag removal and version behavior

- Fix upload response to return actual version (not requested version)
  when artifact already has a version in the package
- Update ref_count tests to use multiple packages (one version per
  artifact per package design constraint)
- Remove allow_public_internet references from upstream caching tests
- Update consistency check test to not assert global system health
- Add versions field to artifact schemas
- Fix dependencies resolution to handle removed tag constraint

backend/app/routes.py

@@ -3433,6 +3433,10 @@ def upload_artifact(
             pkg_version = _create_or_update_version(
                 db, package.id, storage_result.sha256, detected_version, version_source, user_id
             )
+            # Use the actual version from the returned record (may differ if artifact
+            # already had a version in this package)
+            detected_version = pkg_version.version
+            version_source = pkg_version.version_source
         except HTTPException as e:
             # Version conflict (409) - log but don't fail the upload
             if e.status_code == 409:
@@ -4994,6 +4998,19 @@ def get_artifact(artifact_id: str, db: Session = Depends(get_db)):
     if not artifact:
         raise HTTPException(status_code=404, detail="Artifact not found")
 
+    # Get all versions referencing this artifact
+    versions_data = []
+    versions = db.query(PackageVersion).filter(PackageVersion.artifact_id == artifact_id).all()
+    for ver in versions:
+        package = db.query(Package).filter(Package.id == ver.package_id).first()
+        if package:
+            project = db.query(Project).filter(Project.id == package.project_id).first()
+            versions_data.append({
+                "version": ver.version,
+                "package_name": package.name,
+                "project_name": project.name if project else "unknown",
+            })
+
     return ArtifactDetailResponse(
         id=artifact.id,
         sha256=artifact.id,  # SHA256 hash is the artifact ID
@@ -5007,6 +5024,7 @@ def get_artifact(artifact_id: str, db: Session = Depends(get_db)):
         created_by=artifact.created_by,
         ref_count=artifact.ref_count,
         format_metadata=artifact.format_metadata,
+        versions=versions_data,
     )