Wire the Anker Solix EV charger into the per-user integration cascade

Expose the anker-solix plugin to end users the same way as Toyota: a
global -> org -> user settings cascade so everyone can run it under their
own Anker account, with a superadmin (and org admin) able to impose
settings from above.

API Server: integrations_ankersolix.go mirrors integrations.go with the
Anker fields (email + password resolve as a pair from the highest layer,
country resolves on its own), plus GET/PUT/health/chargers routes under
/api/integrations/anker-solix. Secrets and inherited emails are masked;
the live probe runs server-side under the resolved credentials.

Web App: api.js client calls, a second Integrations card in Settings.vue
(scope switch, enable toggle, email/password/country with locked-field
inheritance notes, save + test), and the en.json strings.

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

API Server/internal/api/server.go

@@ -47,6 +47,9 @@
 //	GET    /api/integrations/toyota    PUT    /api/integrations/toyota
 //	POST   /api/integrations/toyota/health
 //	GET    /api/integrations/toyota/vehicles
+//	GET    /api/integrations/anker-solix    PUT    /api/integrations/anker-solix
+//	POST   /api/integrations/anker-solix/health
+//	GET    /api/integrations/anker-solix/chargers
 //
 //	# cars, service records, parts, shares
 //	GET    /api/cars                   POST   /api/cars
@@ -278,6 +281,10 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("PUT /api/integrations/toyota", s.handlePutToyota)
 	mux.HandleFunc("POST /api/integrations/toyota/health", s.handleToyotaHealth)
 	mux.HandleFunc("GET /api/integrations/toyota/vehicles", s.handleToyotaVehicles)
+	mux.HandleFunc("GET /api/integrations/anker-solix", s.handleGetAnker)
+	mux.HandleFunc("PUT /api/integrations/anker-solix", s.handlePutAnker)
+	mux.HandleFunc("POST /api/integrations/anker-solix/health", s.handleAnkerHealth)
+	mux.HandleFunc("GET /api/integrations/anker-solix/chargers", s.handleAnkerChargers)
 
 	// Cars + sharing.
 	mux.HandleFunc("GET /api/cars", s.listCars)