huge chain test, added 1.5% yearly inflation at 3.5 million blocks

include/block/transaction.h

@@ -23,9 +23,20 @@ static inline bool Address_IsCoinbase(const uint8_t address[32]) {
 // 178 bytes total for v1
 typedef struct {
     uint8_t version;
+    // Only one "input" sender address
     uint8_t senderAddress[32];
-    uint8_t recipientAddress[32];
-    uint64_t amount;
+
+    // The "main" recepient address and amount. This is the only required output, and is used for calculating the transaction hash and signature.
+    uint8_t recipientAddress1[32];
+    uint64_t amount1;
+    // The "extra" recepient address and amount. This can safely be NULL/0 if not used and has multiple uses:
+    // - Sending zero: parital spend, sender keeps coins on the same address
+    // - Sending to a different address: normal spend, sender's coins move to a new address, e.g. change address
+    // - Private Transactions: Can nullify the whole original stealth address input (sender) and send change to a new stealth address (recipient 2) to obfuscate the transaction graph.
+    // Note that coinbase will have this as NULL/0 (for now, but we could have multiple payouts in the future)
+    uint8_t recipientAddress2[32];
+    uint64_t amount2;
+
     uint64_t fee; // Rewarded to the miner; can be zero, but the miner may choose to ignore transactions with very low fees
     uint8_t compressedPublicKey[33];
     // Timestamp is dictated by the block