feat: support firmware uploads, OTA pushes

lib/localiser/web/router.ex

@@ -48,12 +48,28 @@ defmodule Localiser.Web.Router do
     get "/onboarding", OnboardingController, :status
   end
 
+  # Firmware download - public (ESP32 devices fetch without auth)
+  scope "/api", Localiser.Web.Controllers do
+    pipe_through :api
+    get "/firmware/:version", FirmwareController, :download
+  end
+
   # User self-service (show own profile)
   scope "/api", Localiser.Web.Controllers do
     pipe_through :authenticated
     get "/users/me", UserController, :me
   end
 
+  # Firmware management - admin only
+  scope "/api", Localiser.Web.Controllers do
+    pipe_through :admin
+    get  "/firmware",               FirmwareController, :index
+    post "/firmware",               FirmwareController, :upload
+    post "/firmware/:version/ota",  FirmwareController, :ota_fleet
+    post "/firmware/:version/ota/instant", FirmwareController, :ota_fleet_instant
+    post "/sensors/:id/ota",        SensorController,   :ota
+  end
+
   # User admin CRUD
   scope "/api", Localiser.Web.Controllers do
     pipe_through :admin