refactor: add gauge_config.h with centralised pin and motion defaults

Gaugecontroller/gauge_config.h

@@ -0,0 +1,31 @@
+#pragma once
+#include <stdint.h>
+
+struct GaugeConfig {
+  // Hardware
+  uint8_t dirPin;
+  uint8_t stepPin;
+  int8_t  enablePin;       // -1 = no enable pin
+  bool    dirInverted;
+  bool    stepActiveHigh;
+  bool    enableActiveLow;
+
+  // Motion defaults (integers; cast to float in setup())
+  long  minPos;
+  long  maxPos;
+  long  homingBackoffSteps;
+  int   maxSpeed;          // steps/s
+  int   accel;             // steps/s²
+  int   homingSpeed;       // steps/s
+};
+
+constexpr GaugeConfig gaugeConfigs[] = {
+  // dir  step  en   dirInv stepHi enLow  min   max   backoff  speed  accel  homeSpd
+  {  48,  49,  -1,  false, true,  true,    0,  3780,   3800,   4000,  6000,    500 },
+  {   8,   9,  -1,  true,  true,  true,    0,  3780,   3800,   4000,  6000,    500 },
+  {  52,  53,  -1,  false, true,  true,    0,  3780,   3800,   4000,  6000,    500 },
+  {  50,  51,  -1,  false, true,  true,    0,  3780,   3800,   4000,  6000,    500 },
+};
+
+static const uint8_t GAUGE_COUNT =
+    sizeof(gaugeConfigs) / sizeof(gaugeConfigs[0]);