Fix architecture test: add continue after forbidden import match and zero-packages guard

- Add isForbidden flag and continue in forbidden suffix loop to prevent
  falling through to the allowed-prefix check, which produced a misleading
  'add it to allowedPrefixes' error for explicitly forbidden imports.
- Add len(agentPkgs)==0 guard to TestAgentPackages_SelfRegister to prevent
  vacuously passing when no agent packages are discovered.

Author: cursoragent

cmd/entire/cli/agent/architecture_test.go

@@ -80,11 +80,16 @@ func TestAgentPackages_NoForbiddenImports(t *testing.T) {
 
 				// Check forbidden suffixes
 				rel := strings.TrimPrefix(imp, repoPrefix)
+				isForbidden := false
 				for _, forbidden := range forbiddenSuffixes {
 					if rel == forbidden || strings.HasPrefix(rel, forbidden+"/") {
 						t.Errorf("forbidden import %q — agent packages must not import %s internals", imp, forbidden)
+						isForbidden = true
 					}
 				}
+				if isForbidden {
+					continue
+				}
 
 				// Check it's in the allowed list
 				allowed := false
@@ -186,6 +191,10 @@ func TestAgentPackages_SelfRegister(t *testing.T) {
 	agentDir := findAgentDir(t)
 	agentPkgs := discoverAgentPackages(t, agentDir)
 
+	if len(agentPkgs) == 0 {
+		t.Fatal("no agent packages found — test setup is broken")
+	}
+
 	for _, pkgDir := range agentPkgs {
 		pkgName := filepath.Base(pkgDir)
 		t.Run(pkgName, func(t *testing.T) {