fix(P01): register orca cert command tree + cert_repo tests (REQ-053)

The `orca cert` command (ca-init, gen, show, renew, fingerprint) was
fully implemented in internal/cli/cert.go but never registered on
rootCmd — unreachable from the CLI. Added init() registration (AD-022).
Added cert_test.go (regression) + cert_smoke_test.go (e2e). Added
cert_repo_test.go (11 tests) + migration 0007 (UNIQUE serial_hex, I-107).

---ci---
project: orca
phase: 1
milestone: v0.7
status: verify
requirements:
  covered: [REQ-053]
  partial: []
---/ci---

internal/cli/cert.go

@@ -253,3 +253,7 @@ func parseFirstCertDER(pemBytes []byte) []byte {
 	}
 	return block.Bytes
 }
+
+func init() {
+	rootCmd.AddCommand(NewCommand(slog.Default()))
+}

internal/cli/cert_smoke_test.go

@@ -0,0 +1,121 @@
+package cli
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func runCertArgs(t *testing.T, args []string) (string, error) {
+	t.Helper()
+	var buf bytes.Buffer
+	rootCmd.SetOut(&buf)
+	rootCmd.SetErr(&buf)
+	rootCmd.SetArgs(args)
+	defer func() {
+		rootCmd.SetArgs(nil)
+		rootCmd.SetOut(os.Stdout)
+		rootCmd.SetErr(os.Stderr)
+	}()
+	err := rootCmd.Execute()
+	return buf.String(), err
+}
+
+func TestCertSmoke(t *testing.T) {
+	t.Setenv("ORCA_HOME", t.TempDir())
+
+	t.Run("ca-init", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "ca-init", "--cn", "test-ca"})
+		if err != nil {
+			t.Fatalf("ca-init: %v\n%s", err, out)
+		}
+		if !strings.Contains(out, "CA initialized") {
+			t.Errorf("ca-init output unexpected: %s", out)
+		}
+	})
+
+	t.Run("gen", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "gen", "--cn", "test-server", "--san", "localhost", "--san", "127.0.0.1"})
+		if err != nil {
+			t.Fatalf("gen: %v\n%s", err, out)
+		}
+		if !strings.Contains(out, "Server cert generated") {
+			t.Errorf("gen output unexpected: %s", out)
+		}
+	})
+
+	t.Run("show", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "show"})
+		if err != nil {
+			t.Fatalf("show: %v\n%s", err, out)
+		}
+		if strings.Contains(out, "PRIVATE KEY") {
+			t.Errorf("show leaked private key material (REQ-035):\n%s", out)
+		}
+	})
+
+	t.Run("fingerprint_ca", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "fingerprint", "--which", "ca"})
+		if err != nil {
+			t.Fatalf("fingerprint ca: %v\n%s", err, out)
+		}
+		fp := strings.TrimSpace(out)
+		if len(fp) != 64 || !isHex(fp) {
+			t.Errorf("ca fingerprint = %q, want 64 hex chars", fp)
+		}
+	})
+
+	t.Run("fingerprint_server", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "fingerprint", "--which", "server"})
+		if err != nil {
+			t.Fatalf("fingerprint server: %v\n%s", err, out)
+		}
+		fp := strings.TrimSpace(out)
+		if len(fp) != 64 || !isHex(fp) {
+			t.Errorf("server fingerprint = %q, want 64 hex chars", fp)
+		}
+	})
+
+	t.Run("renew", func(t *testing.T) {
+		out, err := runCertArgs(t, []string{"cert", "renew"})
+		if err != nil {
+			t.Fatalf("renew: %v\n%s", err, out)
+		}
+		if !strings.Contains(out, "rotated") {
+			t.Errorf("renew output unexpected: %s", out)
+		}
+	})
+
+	t.Run("file_modes", func(t *testing.T) {
+		dir := os.Getenv("ORCA_HOME")
+		checks := []struct {
+			path string
+			want os.FileMode
+		}{
+			{"ca.crt", 0o644},
+			{"ca.key", 0o600},
+			{"server.crt", 0o644},
+			{"server.key", 0o600},
+		}
+		for _, c := range checks {
+			info, err := os.Stat(filepath.Join(dir, c.path))
+			if err != nil {
+				t.Fatalf("stat %s: %v", c.path, err)
+			}
+			if got := info.Mode().Perm(); got != c.want {
+				t.Errorf("mode %s = %04o, want %04o (REQ-033)", c.path, got, c.want)
+			}
+		}
+	})
+}
+
+func isHex(s string) bool {
+	for _, r := range s {
+		if !((r >= '0' && r <= '9') || (r >= 'a' && r <= 'f') || (r >= 'A' && r <= 'F')) {
+			return false
+		}
+	}
+	return true
+}

internal/cli/cert_test.go

@@ -0,0 +1,37 @@
+package cli
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestCertCommandRegistered(t *testing.T) {
+	found := false
+	for _, cmd := range rootCmd.Commands() {
+		if strings.Fields(cmd.Use)[0] == "cert" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("cert command not registered on rootCmd")
+	}
+}
+
+func TestCertSubcommands(t *testing.T) {
+	expected := []string{"ca-init", "gen", "show", "renew", "fingerprint"}
+	registered := make(map[string]bool)
+	for _, cmd := range rootCmd.Commands() {
+		if strings.Fields(cmd.Use)[0] != "cert" {
+			continue
+		}
+		for _, sub := range cmd.Commands() {
+			registered[strings.Fields(sub.Use)[0]] = true
+		}
+	}
+	for _, name := range expected {
+		if !registered[name] {
+			t.Errorf("expected cert subcommand %q not registered", name)
+		}
+	}
+}

internal/cli/init_test.go

@@ -80,8 +80,8 @@ func TestInit_FullBootstrap(t *testing.T) {
 	if err != nil {
 		t.Fatalf("migration version: %v", err)
 	}
-	if version != "0006_node_kind_os.sql" {
-		t.Errorf("migration version = %q, want 0006_node_kind_os.sql", version)
+	if version != "0007_certs_serial_unique.sql" {
+		t.Errorf("migration version = %q, want 0007_certs_serial_unique.sql", version)
 	}
 
 	// Verify localhost node registered with kind=localhost.