diff --git a/internal/cmdregistry/branches_test.go b/internal/cmdregistry/branches_test.go
new file mode 100644
index 000000000..8fe3952b2
--- /dev/null
+++ b/internal/cmdregistry/branches_test.go
@@ -0,0 +1,183 @@
+package cmdregistry
+
+import (
+	"io"
+	"os"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/nself-org/cli/internal/canon"
+	"github.com/spf13/cobra"
+)
+
+func TestEffectiveJSON(t *testing.T) {
+	c := &Command{JSON: canon.JSONEnvelope, Flags: []Flag{
+		{Name: "plain"},
+		{Name: "raw", JSON: strPtr(canon.JSONLegacy)},
+		{Name: "quiet", JSON: strPtr(canon.JSONNone)},
+	}}
+	for _, tc := range []struct {
+		name string
+		set  map[string]bool
+		want string
+	}{
+		{"no flag set keeps the command value", nil, canon.JSONEnvelope},
+		{"flag without override keeps the command value", map[string]bool{"plain": true}, canon.JSONEnvelope},
+		{"unset override flag is ignored", map[string]bool{"plain": true, "raw": false}, canon.JSONEnvelope},
+		{"legacy override replaces envelope", map[string]bool{"raw": true}, canon.JSONLegacy},
+		{"none override replaces envelope", map[string]bool{"quiet": true}, canon.JSONNone},
+		{"none wins over legacy", map[string]bool{"raw": true, "quiet": true}, canon.JSONNone},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := EffectiveJSON(c, tc.set); got != tc.want {
+				t.Fatalf("EffectiveJSON = %q, want %q", got, tc.want)
+			}
+		})
+	}
+	if got := EffectiveJSON(nil, map[string]bool{"raw": true}); got != "" {
+		t.Fatalf("nil command has effective json %q", got)
+	}
+}
+
+func TestBracketedUnclosed(t *testing.T) {
+	for _, tc := range []struct {
+		in, wantTok, wantRest string
+	}{
+		{"<file", "file", ""},
+		{"[opt [nested]", "opt [nested]", ""},
+		{"[a [b]] tail", "a [b]", " tail"},
+	} {
+		open, closeCh := tc.in[0], byte('>')
+		if open == '[' {
+			closeCh = ']'
+		}
+		tok, rest := bracketed(tc.in, open, closeCh)
+		if tok != tc.wantTok || rest != tc.wantRest {
+			t.Errorf("bracketed(%q) = (%q, %q), want (%q, %q)", tc.in, tok, rest, tc.wantTok, tc.wantRest)
+		}
+	}
+	want := []Arg{{Name: "file", Required: true}}
+	if got := parseArgs("get <file"); !reflect.DeepEqual(got, want) {
+		t.Errorf("parseArgs with an unclosed bracket = %v, want %v", got, want)
+	}
+}
+
+func TestApplyFlagEnvNilRegistry(t *testing.T) {
+	err := ApplyFlagEnv(nil, map[string]map[string]string{"nself": {"x": "X"}}, nil, true)
+	if err == nil || !strings.Contains(err.Error(), "needs a registry") {
+		t.Fatalf("nil registry accepted: %v", err)
+	}
+}
+
+func TestBuildNeedsRootAndCanon(t *testing.T) {
+	if _, err := Build(nil, fixtureCanon(t), nil, BuildOptions{}); err == nil || !strings.Contains(err.Error(), "needs a root command") {
+		t.Fatalf("nil root accepted: %v", err)
+	}
+	if _, err := Build(fixtureRoot(false), nil, nil, BuildOptions{}); err == nil || !strings.Contains(err.Error(), "needs a root command") {
+		t.Fatalf("nil canon accepted: %v", err)
+	}
+}
+
+func TestBuildV15OnlyEnvelopeMustResolve(t *testing.T) {
+	opts := fixtureOpts(true)
+	opts.V15OnlyEnvelope = map[string]bool{"ghost": true}
+	_, err := Build(fixtureRoot(false), fixtureCanon(t), fixtureTypes(), opts)
+	if err == nil || !strings.Contains(err.Error(), `V15OnlyEnvelope["ghost"]`) {
+		t.Fatalf("unresolved V15OnlyEnvelope path accepted: %v", err)
+	}
+}
+
+func TestBuiltinMountKeepsPresplitCanonInV14(t *testing.T) {
+	root := fixtureRoot(false)
+	root.AddCommand(&cobra.Command{Use: "fixture", RunE: noop, Annotations: map[string]string{annPluginKey: "fixture", annSourceKey: sourceBuiltin}})
+	f := fixtureCanon(t)
+	f.Commands["fixture"] = canon.Entry{Canon: canon.CanonPending, SideEffect: canon.SideEffectRead}
+	r, err := Build(root, f, fixtureTypes(), fixtureOpts(false))
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, ok := r.Lookup("nself fixture")
+	if !ok || c.Canon != canon.CanonPending || c.Plugin != nil {
+		t.Fatalf("v1.4 builtin family must keep its canon classification and have no plugin identity: %+v, found=%t", c, ok)
+	}
+}
+
+func TestValidateConfirmProblems(t *testing.T) {
+	cmd := &cobra.Command{Use: "reset", RunE: noop}
+	cmd.Flags().Bool("yes", false, "")
+	declared := localFlags(cmd)
+	for _, tc := range []struct {
+		name     string
+		src      *canon.Confirm
+		runnable bool
+		want     string
+	}{
+		{"not runnable", &canon.Confirm{Flags: []string{"yes"}}, false, "command is not runnable"},
+		{"duplicate flag", &canon.Confirm{Flags: []string{"yes", "yes"}}, true, "empty or duplicated"},
+		{"empty flag", &canon.Confirm{Flags: []string{""}}, true, "empty or duplicated"},
+		{"plan without flags", &canon.Confirm{Flags: []string{"yes"}, Plan: &canon.PlanForm{}}, true, "flag and id_flag are required"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			confirm, problems := validateConfirm("reset", tc.src, tc.runnable, cmd, declared)
+			if confirm != nil {
+				t.Fatalf("invalid confirm produced a value: %+v", confirm)
+			}
+			if len(problems) == 0 || !strings.Contains(strings.Join(problems, "\n"), tc.want) {
+				t.Fatalf("want a problem containing %q, got %v", tc.want, problems)
+			}
+		})
+	}
+}
+
+// captureStderr runs fn with os.Stderr redirected and returns what it wrote.
+func captureStderr(t *testing.T, fn func()) string {
+	t.Helper()
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	old := os.Stderr
+	os.Stderr = w
+	defer func() { os.Stderr = old }()
+	fn()
+	w.Close()
+	b, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(b)
+}
+
+func TestWarnPluginOncePerSlug(t *testing.T) {
+	warned := map[string]bool{}
+	out := captureStderr(t, func() {
+		warnPlugin("demo", warned, "invalid surface")
+		warnPlugin("demo", warned, "invalid surface")
+		warnPlugin("other", warned, "invalid confirm JSON")
+	})
+	if got := strings.Count(out, "\n"); got != 2 {
+		t.Fatalf("want one warning per slug (2 lines), got %d: %q", got, out)
+	}
+	if !strings.Contains(out, "[E437] plugin demo: invalid surface; confirm disabled") || !strings.Contains(out, "plugin other: invalid confirm JSON") {
+		t.Fatalf("unexpected warning text: %q", out)
+	}
+}
+
+func TestPluginInvalidConfirmJSONIsDropped(t *testing.T) {
+	root := pluginFixture()
+	cmd, _, err := root.Find([]string{"demo", "sub"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	cmd.Annotations[annConfirmKey] = `{not json`
+	var r *Registry
+	out := captureStderr(t, func() { r = mustBuild(t, root, true) })
+	c, ok := r.Lookup("nself demo sub")
+	if !ok || c.Confirm != nil {
+		t.Fatalf("invalid confirm JSON must not create a confirm: %+v, found=%t", c, ok)
+	}
+	if !strings.Contains(out, "invalid confirm JSON") {
+		t.Fatalf("no warning for invalid confirm JSON: %q", out)
+	}
+}