Remove dynamic memory allocation (malloc/calloc/free)

- Add static memory pool implementation (se050_mem_pool.c/h)
- Replace all malloc/calloc with pool allocations
- Replace all free with pool deallocations
- Remove strdup usage (use fixed-size buffer instead)
- Update I2C HAL to use fixed-size dev_path array
- All 24 tests pass with static memory only

Suitable for embedded environments (u-boot, ESP32) without heap.

include/se050_i2c_hal.h

@@ -7,6 +7,8 @@
 #define SE050_I2C_HAL_H
 
 #include <stdint.h>
+#include <stddef.h>
+#include <string.h>
 
 /* Status codes */
 typedef enum {
@@ -24,10 +26,12 @@ typedef enum {
 } se050_status_t;
 
 /* I2C HAL structure */
+#define SE050_I2C_DEV_PATH_MAX  64
+
 typedef struct {
     void *handle;           /**< I2C file descriptor */
     uint8_t slave_addr;     /**< I2C slave address */
-    const char *dev_path;   /**< I2C device path */
+    char dev_path[SE050_I2C_DEV_PATH_MAX];  /**< I2C device path */
     int wakeup_pin;         /**< Wakeup GPIO pin (-1 if unused) */
 } se050_i2c_hal_t;
 

include/se050_mem_pool.h

@@ -0,0 +1,106 @@
+/**
+ * @file se050_mem_pool.h
+ * @brief Static Memory Pool for Embedded Systems
+ * 
+ * Replaces malloc/calloc with pre-allocated static pools.
+ * Suitable for u-boot, ESP32, and other embedded environments.
+ */
+
+#ifndef SE050_MEM_POOL_H
+#define SE050_MEM_POOL_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+/* Configuration: Pool sizes */
+#ifndef SE050_POOL_SESSION_COUNT
+#define SE050_POOL_SESSION_COUNT    4
+#endif
+
+#ifndef SE050_POOL_SCP03_COUNT
+#define SE050_POOL_SCP03_COUNT      4
+#endif
+
+#ifndef SE050_POOL_KEYSTORE_COUNT
+#define SE050_POOL_KEYSTORE_COUNT   2
+#endif
+
+#ifndef SE050_POOL_KEYSTORE_MAX_OBJECTS
+#define SE050_POOL_KEYSTORE_MAX_OBJECTS  8
+#endif
+
+#ifndef SE050_POOL_RNG_COUNT
+#define SE050_POOL_RNG_COUNT        2
+#endif
+
+#ifndef SE050_POOL_I2C_HAL_COUNT
+#define SE050_POOL_I2C_HAL_COUNT    2
+#endif
+
+/* Forward declarations */
+struct se050_session_ctx;
+struct se050_scp03_ctx;
+struct se050_keystore_ctx;
+struct se050_rng_ctx;
+struct se050_i2c_hal;
+
+/* ============================================================================
+ * Memory Pool API
+ * ============================================================================ */
+
+/**
+ * @brief Initialize all memory pools
+ * 
+ * Must be called before any other SE050 functions.
+ * 
+ * @return 0 on success, -1 on error
+ */
+int se050_mem_pool_init(void);
+
+/**
+ * @brief Cleanup all memory pools
+ * 
+ * Zeroizes all allocated memory before freeing.
+ */
+void se050_mem_pool_cleanup(void);
+
+/* Session pool */
+struct se050_session_ctx *se050_session_alloc_pool(void);
+void se050_session_free_pool(struct se050_session_ctx *ctx);
+
+/* SCP03 pool */
+struct se050_scp03_ctx *se050_scp03_alloc_pool(void);
+void se050_scp03_free_pool(struct se050_scp03_ctx *ctx);
+
+/* Keystore pool */
+struct se050_keystore_ctx *se050_keystore_alloc_pool(void);
+void se050_keystore_free_pool(struct se050_keystore_ctx *ctx);
+
+/* RNG pool */
+struct se050_rng_ctx *se050_rng_alloc_pool(void);
+void se050_rng_free_pool(struct se050_rng_ctx *ctx);
+
+/* I2C HAL pool */
+struct se050_i2c_hal *se050_i2c_hal_alloc_pool(void);
+void se050_i2c_hal_free_pool(struct se050_i2c_hal *hal);
+
+/* ============================================================================
+ * Debug/Statistics
+ * ============================================================================ */
+
+/**
+ * @brief Get pool statistics
+ */
+typedef struct {
+    int total;
+    int used;
+    int free;
+} se050_pool_stats_t;
+
+void se050_mem_pool_stats(se050_pool_stats_t *session,
+                          se050_pool_stats_t *scp03,
+                          se050_pool_stats_t *keystore,
+                          se050_pool_stats_t *rng,
+                          se050_pool_stats_t *i2c_hal);
+
+#endif /* SE050_MEM_POOL_H */

include/se050_scp03.h

@@ -12,6 +12,7 @@
 
 /* Forward declarations */
 typedef struct se050_session_ctx se050_session_ctx_t;
+typedef struct se050_scp03_ctx se050_scp03_ctx_t;
 
 /* SCP03 key sizes */
 #define SCP03_KEY_SIZE  16

include/se050_session_internal.h

@@ -10,6 +10,7 @@
 #ifndef SE050_SESSION_INTERNAL_H
 #define SE050_SESSION_INTERNAL_H
 
+#include "se050_i2c_hal.h"
 #include "se050_wireguard.h"
 #include <stdint.h>