Add proboctl CLI and move seed commands into it

Introduce a new proboctl Cobra CLI for Probo instance management
that connects directly to PostgreSQL. Move the standalone
common-third-parties-import and common-tracker-patterns-import
commands into proboctl as `proboctl seed common-third-parties`
and `proboctl seed common-tracker-patterns`, replacing flag-based
PG connection with a shared factory pattern.

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

pkg/proboctl/root/root.go

@@ -0,0 +1,45 @@
+// 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 root
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+	"go.probo.inc/probo/pkg/proboctl/cmdutil"
+	"go.probo.inc/probo/pkg/proboctl/seed"
+	"go.probo.inc/probo/pkg/proboctl/version"
+)
+
+func NewCmdRoot(f *cmdutil.Factory) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:           "proboctl <command> [flags]",
+		Short:         "Probo instance management CLI",
+		SilenceUsage:  true,
+		SilenceErrors: true,
+	}
+
+	cmd.PersistentFlags().StringVar(
+		&f.PgDSN,
+		"pg-dsn",
+		os.Getenv("DATABASE_URL"),
+		"PostgreSQL connection URL (default: DATABASE_URL env)",
+	)
+
+	cmd.AddCommand(seed.NewCmdSeed(f))
+	cmd.AddCommand(version.NewCmdVersion(f))
+
+	return cmd
+}