Add selectable ESP-NOW send path for accel/tap input.

Expose best_effort/fast/wait/reliable via UART, dashboard, and CLI so
loss vs latency can be compared under real multi-pod load.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/api_input_send_mode.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+
+	pb "powerpod/gotool/pb"
+)
+
+type inputSendModeAPIResponse struct {
+	Success       bool   `json:"success"`
+	Mode          uint32 `json:"mode"`
+	ModeName      string `json:"mode_name"`
+	ClientID      uint32 `json:"client_id,omitempty"`
+	SlavesUpdated uint32 `json:"slaves_updated,omitempty"`
+	Error         string `json:"error,omitempty"`
+}
+
+func inputSendModeName(mode pb.InputSendMode) string {
+	switch mode {
+	case pb.InputSendMode_INPUT_SEND_BEST_EFFORT:
+		return "best_effort"
+	case pb.InputSendMode_INPUT_SEND_FAST:
+		return "fast"
+	case pb.InputSendMode_INPUT_SEND_WAIT:
+		return "wait"
+	case pb.InputSendMode_INPUT_SEND_RELIABLE:
+		return "reliable"
+	default:
+		return "unknown"
+	}
+}
+
+func mountInputSendModeAPI(mux *http.ServeMux, link *managedSerial) {
+	mux.HandleFunc("/api/input-send-mode", func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet:
+			serveInputSendModeGet(w, link)
+		case http.MethodPut, http.MethodPost:
+			serveInputSendModePut(w, r, link)
+		default:
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		}
+	})
+}
+
+func serveInputSendModeGet(w http.ResponseWriter, link *managedSerial) {
+	resp, err := link.InputSendMode(&pb.InputSendModeRequest{Write: false})
+	if err != nil {
+		writeJSON(w, http.StatusBadGateway, inputSendModeAPIResponse{Error: err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, inputSendModeAPIResponse{
+		Success:  resp.GetSuccess(),
+		Mode:     uint32(resp.GetMode()),
+		ModeName: inputSendModeName(resp.GetMode()),
+	})
+}
+
+func serveInputSendModePut(w http.ResponseWriter, r *http.Request, link *managedSerial) {
+	var body struct {
+		Mode       uint32 `json:"mode"`
+		ClientID   uint32 `json:"client_id"`
+		AllClients bool   `json:"all_clients"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeJSON(w, http.StatusBadRequest, inputSendModeAPIResponse{Error: "invalid JSON"})
+		return
+	}
+	if body.Mode > uint32(pb.InputSendMode_INPUT_SEND_RELIABLE) {
+		writeJSON(w, http.StatusBadRequest, inputSendModeAPIResponse{Error: "mode must be 0..3"})
+		return
+	}
+	if !body.AllClients && body.ClientID == 0 {
+		// Dashboard default: apply to every registered slave.
+		body.AllClients = true
+	}
+
+	resp, err := link.InputSendMode(&pb.InputSendModeRequest{
+		Write:      true,
+		Mode:       pb.InputSendMode(body.Mode),
+		ClientId:   body.ClientID,
+		AllClients: body.AllClients,
+	})
+	if err != nil {
+		writeJSON(w, http.StatusBadGateway, inputSendModeAPIResponse{Error: err.Error()})
+		return
+	}
+	status := http.StatusOK
+	if !resp.GetSuccess() {
+		status = http.StatusBadRequest
+	}
+	writeJSON(w, status, inputSendModeAPIResponse{
+		Success:       resp.GetSuccess(),
+		Mode:          uint32(resp.GetMode()),
+		ModeName:      inputSendModeName(resp.GetMode()),
+		ClientID:      resp.GetClientId(),
+		SlavesUpdated: resp.GetSlavesUpdated(),
+	})
+}