Add OCPP control for the Anker Solix EV charger (Own/Proxy CSMS)

The Anker Solix connector was read-only (cloud monitoring only). Add an
OCPP 1.6J control path with a per-user, cascading control mode:

  - off   monitoring only (default, unchanged behavior)
  - own   DriverVault is the charger's Central System (full control)
  - proxy DriverVault relays to Anker's cloud and injects commands

New internal/ocpp subsystem (stdlib-only, hand-rolled RFC 6455): a CSMS
with session management, inbound dispatch, and typed control commands
(RemoteStart/Stop, SetChargingProfile current limit, ChangeAvailability,
Reset, UnlockConnector, TriggerMessage, Get/ChangeConfiguration). Own- and
proxy-mode paths are verified end-to-end against a simulated charge point.

The charger connects to /ocpp/{serial}, authenticated with OCPP Basic auth
(serial + a per-charger control token) resolved to the owning user via an
in-memory token index. Control REST endpoints mirror the monitoring ones and
reuse the same cascade gate plus a live-session check. controlMode is a new
cascade field (global -> org -> user) advertised as a select on the plugin.

Frontend: control-mode select + provisioning card in Settings, and a real
Start/Stop/limit/reset control panel in Charging, gated on the active mode.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

API Server/internal/api/server.go

@@ -104,13 +104,16 @@
 package api
 
 import (
+	"bufio"
 	"context"
 	"log"
+	"net"
 	"net/http"
 	"sync"
 	"time"
 
 	"drivervault/apiserver/internal/config"
+	"drivervault/apiserver/internal/ocpp"
 	"drivervault/apiserver/internal/pb"
 	"drivervault/apiserver/internal/plugins"
 	_ "drivervault/apiserver/internal/plugins/builtin" // register built-in plugins
@@ -136,6 +139,13 @@ type Server struct {
 	cfg     config.Config
 	pb      *pb.Client
 	plugins *plugins.Manager
+
+	// ocpp is the OCPP 1.6J Central System that Anker Solix chargers connect to
+	// when their owner picks a control mode of own/proxy (see internal/ocpp and
+	// integrations_ankersolix_control.go). Nil-safe: control endpoints report a
+	// clear error when a charger is not connected.
+	ocpp    *ocpp.CSMS
+	control *controlIndex // token -> owning user/charger for the /ocpp endpoint
 }
 
 // New constructs a Server around an already-built PocketBase client.
@@ -144,14 +154,19 @@ func New(cfg config.Config, client *pb.Client) *Server {
 		cfg:     cfg,
 		pb:      client,
 		plugins: plugins.NewManager(cfg.PluginsFile),
+		ocpp:    ocpp.NewCSMS(func(f string, a ...any) { log.Printf("ocpp: "+f, a...) }),
+		control: newControlIndex(),
 	}
 }
 
 // StartPlugins loads persisted plugin state and initialises enabled plugins.
 func (s *Server) StartPlugins() error { return s.plugins.Load() }
 
-// Stop releases server-held resources (currently: plugin instances).
-func (s *Server) Stop(ctx context.Context) { s.plugins.Shutdown(ctx) }
+// Stop releases server-held resources (plugin instances and OCPP sessions).
+func (s *Server) Stop(ctx context.Context) {
+	s.ocpp.Shutdown(ctx)
+	s.plugins.Shutdown(ctx)
+}
 
 // usersCollection returns the PocketBase auth collection holding app users.
 func (s *Server) usersCollection() string {
@@ -286,6 +301,18 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("POST /api/integrations/anker-solix/health", s.handleAnkerHealth)
 	mux.HandleFunc("GET /api/integrations/anker-solix/chargers", s.handleAnkerChargers)
 
+	// Anker Solix OCPP control (per-charger; gated by the same cascade plus a
+	// control mode of own/proxy and a live CSMS session). See
+	// integrations_ankersolix_control.go.
+	mux.HandleFunc("GET /api/integrations/anker-solix/chargers/{sn}/control", s.handleAnkerControlStatus)
+	mux.HandleFunc("POST /api/integrations/anker-solix/chargers/{sn}/control/token", s.handleAnkerControlToken)
+	mux.HandleFunc("POST /api/integrations/anker-solix/chargers/{sn}/{action}", s.handleAnkerControlAction)
+
+	// OCPP WebSocket endpoint the charger dials out to (own/proxy modes). It sits
+	// outside /api/ so it bypasses bearer auth; it authenticates the charger with
+	// OCPP Basic auth (serial + per-charger control token) instead.
+	mux.HandleFunc("GET /ocpp/{serial}", s.handleOCPPConnect)
+
 	// Cars + sharing.
 	mux.HandleFunc("GET /api/cars", s.listCars)
 	mux.HandleFunc("POST /api/cars", s.createCar)
@@ -454,3 +481,15 @@ func (w *statusWriter) Write(b []byte) (int, error) {
 	w.wrote = true
 	return w.ResponseWriter.Write(b)
 }
+
+// Hijack lets the wrapped ResponseWriter be taken over for a protocol switch
+// (the OCPP WebSocket upgrade at /ocpp/{serial}). Without this pass-through the
+// logging middleware would hide the underlying http.Hijacker.
+func (w *statusWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	hj, ok := w.ResponseWriter.(http.Hijacker)
+	if !ok {
+		return nil, nil, http.ErrNotSupported
+	}
+	w.wrote = true // a hijacked connection writes its own response
+	return hj.Hijack()
+}