Opening a shop is an API call; the broker learns of it in the same request

The last step of onboarding that needed a shell: provision site printed
a broker password and a person typed it into Mosquitto's passwd file on
the host - mounted read-only in the container, so the first attempt
failed silently and the password was re-rolled. No tenant could open a
second branch without us.

The server now drives Mosquitto's dynamic-security plugin over its own
broker login: POST /api/sites (owner) writes the row and the sealed
password, registers the login and a per-site role with literal topics
(the 2.0 plugin does not substitute %u - measured), and removes the row
again if the broker refuses, so a shop cannot exist in the database and
not on the broker. provision site goes through the same path. The
head-office Shops screen gets 'Open a new shop'.

broker-init converts the existing passwd file into the plugin's store
with every hash intact - PBKDF2-SHA512 both sides - so the cutover
re-claims no shop PC. Rehearsed locally: old logins keep working,
isolation holds, the health probe works, and a PC claiming a shop opened
through the API connects as that shop. run-local.sh now brings the
broker up the same way.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KGcjxF1cNLcuwc3DAPcnfj

server/cmd/behavision-server/brokerinit.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/loyaly/behavision-server/internal/broker"
+)
+
+// broker-init converts Mosquitto's passwd file into the dynamic-security
+// plugin's store, once, at cutover. After it the broker is driven over MQTT
+// and the passwd and acl files are no longer read.
+func runBrokerInit(args []string) error {
+	fs := flag.NewFlagSet("broker-init", flag.ExitOnError)
+	passwd := fs.String("passwd", "", "path to the mosquitto passwd file to convert")
+	out := fs.String("out", "", "where to write dynamic-security.json (must be writable by the broker)")
+	backend := fs.String("backend-user", "behavision-backend", "the server's own broker username; becomes the plugin admin")
+	health := fs.String("health-user", "health", "the healthcheck username")
+	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, `usage: behavision-server broker-init -passwd FILE -out FILE
+
+Converts a mosquitto_passwd file into the dynamic-security plugin's store,
+keeping every password hash exactly as it is, so no shop PC has to be
+re-claimed. Then in mosquitto.conf replace password_file/acl_file with:
+
+  per_listener_settings false
+  plugin /usr/lib/mosquitto_dynamic_security.so
+  plugin_opt_config_file /mosquitto/data/dynamic-security.json
+
+and restart the broker. From then on 'provision site' and POST /api/sites
+register a shop's login themselves.
+`)
+		fs.PrintDefaults()
+	}
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+	if *passwd == "" || *out == "" {
+		fs.Usage()
+		return errors.New("-passwd and -out are required")
+	}
+	f, err := os.Open(*passwd)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	st, err := broker.FromPasswd(f, *backend, *health)
+	if err != nil {
+		return err
+	}
+	if _, err := os.Stat(*out); err == nil {
+		return fmt.Errorf("%s already exists - refusing to overwrite a live store", *out)
+	}
+	w, err := os.OpenFile(*out, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o600)
+	if err != nil {
+		return err
+	}
+	defer w.Close()
+	if err := st.Encode(w); err != nil {
+		return err
+	}
+	fmt.Printf("wrote %s: %d clients, %d roles\n", *out, len(st.Clients), len(st.Roles))
+	for _, c := range st.Clients {
+		fmt.Printf("  %-28s %s\n", c.Username, c.Roles[0].Rolename)
+	}
+	return nil
+}