chore(core): improve unit_properties module comments

diff --git a/core/embed/util/unit_properties/inc/util/unit_properties.h b/core/embed/util/unit_properties/inc/util/unit_properties.h
index 47f1f2c58..853aeae64 100644
--- a/core/embed/util/unit_properties/inc/util/unit_properties.h
+++ b/core/embed/util/unit_properties/inc/util/unit_properties.h
@@ -25,47 +25,91 @@
 
 #ifdef SECURE_MODE
 
-// Initializes module a detects the unit properties
-//
-// Returns `true` if the properties are successfully detected
+/**
+ * @brief Initializes module and detects the unit properties
+ *
+ * @return true if the properties are successfully detected
+ * @return false otherwise
+ */
 bool unit_properties_init(void);
 
 #endif  // SECURE_MODE
 
 typedef struct {
-  // Set to true if the unit properties are locked and cannot be changed
-  // (the device is in the production mode)
+  /**
+   * Production lock status indicator.
+   * When set to true, the unit properties are locked and cannot be modified.
+   * This indicates the device is in production mode and configuration is
+   * finalized.
+   */
   bool locked;
 
-  // Unit color. The value is opaque to the firmware and is
-  // used only by Trezor Suite.
+  /**
+   * Unit color identifier.
+   * This field contains a hardware-specific color code that is opaque to the
+   * firmware. The value is interpreted and displayed by Trezor Suite for user
+   * identification purposes.
+   */
   uint8_t color;
-  // Set if `color` field contains a valid value
+  /** Validity flag for the color field - set to true when color contains a
+   * valid value */
   bool color_is_valid;
 
-  // Unit packaging. The value is opaque for the firmware and is
-  // used only by Trezor Suite.
+  /**
+   * Unit packaging type identifier.
+   * This field contains a packaging-specific code that is opaque to the
+   * firmware. The value is used by Trezor Suite to determine the device's
+   * packaging variant.
+   */
   uint8_t packaging;
-  // Set if `packaging` field contains a valid value
+  /** Validity flag for the packaging field - set to true when packaging
+   * contains a valid value */
   bool packaging_is_valid;
 
-  // Set to true if the unit is BTC only
+  /**
+   * Bitcoin-only firmware restriction flag.
+   * When set to true, indicates this unit is configured to run Bitcoin-only
+   * firmware, restricting functionality to Bitcoin-related operations only.
+   */
   bool btconly;
-  // Set if `btconly` field contains a valid value
+  /** Validity flag for the btconly field - set to true when btconly contains a
+   * valid value */
   bool btconly_is_valid;
 
-  // Set to true if the SD card hotswap is enabled
+  /**
+   * SD card hotswap capability flag.
+   * When set to true, indicates the unit supports hot-swapping of SD cards
+   * without requiring a system restart or power cycle.
+   */
   bool sd_hotswap_enabled;
 
 } unit_properties_t;
 
-// Gets a copy of unit properties structure
-//
-// Properties are detected just once during the initialization.
+/**
+ * @brief Gets a copy of unit properties structure
+ *
+ * Properties are detected just once during the initialization.
+ *
+ * @param props Pointer to the structure to fill with unit properties
+ */
 void unit_properties_get(unit_properties_t* props);
 
-// Gets a pointer to the static unit properties structure
+/**
+ * @brief Gets a pointer to the static unit properties structure
+ *
+ * @return const unit_properties_t* Pointer to the static unit properties
+ * structure
+ */
 const unit_properties_t* unit_properties(void);
 
+/**
+ * @brief Gets the device serial number
+ *
+ * @param device_sn Buffer to store the device serial number
+ * @param max_device_sn_size Maximum size of the device_sn buffer
+ * @param device_sn_size Pointer to store the actual size of the serial number
+ * @return true if the serial number was successfully retrieved
+ * @return false otherwise
+ */
 bool unit_properties_get_sn(uint8_t* device_sn, size_t max_device_sn_size,
                             size_t* device_sn_size);