cmd/tsconnect: use empty string as the default state store key

Makes the Wasm client more similar to the others, and allows the default
profile to be correctly picked up when restarting the client in dev
mode (where we persist the state in sessionStorage).

Also update README to reflect that Go wasm changes can be picked up
with just a reload (as of #5383)

Signed-off-by: Mihai Parparita <mihai@tailscale.com>

cmd/tsconnect/README.md

@@ -11,7 +11,7 @@ To start the development server:
 ./tool/go run ./cmd/tsconnect dev
 ```
 
-The site is served at http://localhost:9090/. JavaScript and CSS changes can be picked up with a browser reload. Go changes (including to the `wasm` package) require the server to be stopped and restarted. In development mode the state the Tailscale client is stored in `sessionStorage` and will thus survive page reloads (but not the tab being closed).
+The site is served at http://localhost:9090/. JavaScript, CSS and Go `wasm` package changes can be picked up with a browser reload. Server-side Go changes require the server to be stopped and restarted. In development mode the state the Tailscale client state is stored in `sessionStorage` and will thus survive page reloads (but not the tab being closed).
 
 ## Deployment
 

cmd/tsconnect/wasm/wasm_js.go

@@ -124,7 +124,7 @@ func newIPN(jsConfig js.Value) map[string]any {
 
 	logid := lpc.PublicID.String()
 	srv := ipnserver.New(logf, logid)
-	lb, err := ipnlocal.NewLocalBackend(logf, logid, store, "wasm", dialer, eng, controlclient.LoginEphemeral)
+	lb, err := ipnlocal.NewLocalBackend(logf, logid, store, "", dialer, eng, controlclient.LoginEphemeral)
 	if err != nil {
 		log.Fatalf("ipnlocal.NewLocalBackend: %v", err)
 	}