Error handling on system boot (#30)

Implements #3

Reviewed-on: #30
Co-authored-by: localhorst <localhorst@mosad.xyz>
Co-committed-by: localhorst <localhorst@mosad.xyz>

main/outputs.h

@@ -1,15 +1,70 @@
+/**
+ * @file outputs.h
+ * @brief Output control for circulation pump, burner, and safety contact.
+ *
+ * This module controls the relay outputs via GPIO pins. All outputs
+ * are active-low (relay energized when GPIO is low).
+ */
+
 #pragma once
 
+#include "esp_err.h"
+
+/**
+ * @brief Output state enumeration.
+ */
 typedef enum _Output
 {
-    ENABLED,
-    DISABLED
+    ENABLED, /**< Output active (relay energized, GPIO low). */
+    DISABLED /**< Output inactive (relay de-energized, GPIO high). */
 } eOutput;
 
-void initOutputs(void);
+/**
+ * @brief Initialize the outputs module.
+ *
+ * Configures GPIO pins for circulation pump, burner, and safety contact
+ * as outputs. All outputs are initialized to DISABLED (safe state).
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initOutputs(void);
+
+/**
+ * @brief Get the current circulation pump state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getCirculationPumpState(void);
+
+/**
+ * @brief Set the circulation pump state.
+ * @param in Desired state (ENABLED or DISABLED).
+ */
 void setCirculationPumpState(eOutput in);
+
+/**
+ * @brief Get the current burner state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getBurnerState(void);
+
+/**
+ * @brief Set the burner state.
+ * @param in Desired state (ENABLED or DISABLED).
+ */
 void setBurnerState(eOutput in);
+
+/**
+ * @brief Get the current safety contact state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getSafetyControlState(void);
-void setSafetyControlState(eOutput in);
+
+/**
+ * @brief Set the safety contact state.
+ *
+ * The safety contact controls power to the burner. When DISABLED,
+ * the burner cannot operate regardless of the burner signal.
+ *
+ * @param in Desired state (ENABLED or DISABLED).
+ */
+void setSafetyControlState(eOutput in);