Add proboctl internal admin CLI with cookie-banner set-branding command

New staff-only CLI that connects directly to PostgreSQL (via PG_*
env vars) to manage parameters not exposed through the public API.
First command: proboctl cookie-banner set-branding <id> <true|false>

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/proboctl/root.go

@@ -0,0 +1,102 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package proboctl
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/spf13/cobra"
+	"go.gearno.de/kit/pg"
+	"go.probo.inc/probo/pkg/proboctl/cookiebanner"
+)
+
+func NewRootCmd(version string) *cobra.Command {
+	var pgDSN string
+
+	cmd := &cobra.Command{
+		Use:           "proboctl <command> [flags]",
+		Short:         "Probo internal admin CLI",
+		Long:          "proboctl is an internal tool for Probo staff to manage parameters not exposed through the public API.",
+		SilenceUsage:  true,
+		SilenceErrors: true,
+	}
+
+	cmd.PersistentFlags().StringVar(&pgDSN, "pg-dsn", "", "PostgreSQL connection string (also PG_DSN env var)")
+
+	newPG := func() (*pg.Client, error) {
+		return newPGClient(pgDSN)
+	}
+
+	cmd.AddCommand(cookiebanner.NewCmdCookieBanner(newPG))
+
+	return cmd
+}
+
+func newPGClient(flagDSN string) (*pg.Client, error) {
+	dsn := flagDSN
+	if dsn == "" {
+		dsn = os.Getenv("PG_DSN")
+	}
+
+	var addr, user, pass, db string
+
+	if dsn != "" {
+		cfg, err := pgx.ParseConfig(dsn)
+		if err != nil {
+			return nil, fmt.Errorf("invalid DSN: %w", err)
+		}
+		addr = fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
+		user = cfg.User
+		pass = cfg.Password
+		db = cfg.Database
+	} else {
+		addr = envOrDefault("PG_ADDR", "localhost:5432")
+		user = envOrDefault("PG_USERNAME", "postgres")
+		pass = envOrDefault("PG_PASSWORD", "postgres")
+		db = envOrDefault("PG_DATABASE", "probod")
+	}
+
+	poolSize := envIntOrDefault("PG_POOL_SIZE", 2)
+
+	opts := []pg.Option{
+		pg.WithAddr(addr),
+		pg.WithUser(user),
+		pg.WithPassword(pass),
+		pg.WithDatabase(db),
+		pg.WithPoolSize(int32(poolSize)),
+	}
+
+	return pg.NewClient(opts...)
+}
+
+func envOrDefault(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}
+
+func envIntOrDefault(key string, fallback int) int {
+	if v := os.Getenv(key); v != "" {
+		if n, err := strconv.Atoi(v); err == nil {
+			return n
+		}
+		fmt.Fprintf(os.Stderr, "warning: invalid %s value %q, using default %d\n", key, v, fallback)
+	}
+	return fallback
+}