Node Update TON 2026.07

Following the voting and activation of TON 2026.06, mainnet data from July 22 showed reduced efficiency among some validators. This lowered the average masterchain block rate from ~2.47 to ~2.30 blocks per second, also reduced shardchain block rates, and increased latency for some user operations.

This behavior was not observed during testnet or local testing.

TON 2026.07 retains the legacy broadcast mechanism for now and introduces improvements to the new broadcast mechanism to better account for mainnet conditions.

@tonstatus233