feat(c-miner): port miner pipeline to modular C implementation

block_builder.h

@@ -0,0 +1,40 @@
+#ifndef BLOCK_BUILDER_H
+#define BLOCK_BUILDER_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "types.h"
+
+char *tx_encode_coinbase_height(int height);
+int is_segwit_tx(const char *raw_hex);
+int build_coinbase_transaction(
+    const BlockTemplate *tpl,
+    const char *miner_script_pubkey,
+    const char *extranonce1,
+    const char *extranonce2,
+    const char *coinbase_message,
+    char **coinbase_hex_out,
+    char **coinbase_txid_out
+);
+char *calculate_merkle_root(const char *coinbase_txid_hex, const TemplateTransaction *txs, size_t tx_count);
+int build_block_header_bytes(
+    int version,
+    const char *prev_hash_hex,
+    const char *merkle_root_hex,
+    uint32_t timestamp,
+    const char *bits_hex,
+    uint32_t nonce,
+    uint8_t out_header[80]
+);
+char *build_block_header_hex(
+    int version,
+    const char *prev_hash_hex,
+    const char *merkle_root_hex,
+    uint32_t timestamp,
+    const char *bits_hex,
+    uint32_t nonce
+);
+char *serialize_block(const char *header_hex, const char *coinbase_tx_hex, const TemplateTransaction *txs, size_t tx_count);
+
+#endif