Move Taproot signaling start date earlier to allow more time for miner
preparation and coordination before the March 2027 timeout.
Consensus changes:
- Mainnet activation start: February 14, 2026 (was March 1, 2026)
- Mainnet timeout: March 1, 2027 (unchanged)
- Update nStartTime: 1771027200 (was 1772323200)
- Applied to both mainnet and testnet deployments
This extends the signaling window from 12 months to 12.5 months, providing
miners additional time to upgrade and signal readiness for Taproot activation
Update testnet minimum chain work and default assume valid values to current state.
Restore security check in getblocktemplate RPC to prevent usage during initial block download.
- Change BIP34Height from 0 to 8192 to match mainnet activation
- Adjust nPowTargetTimespan from 1 day to 14 days for better difficulty stability
- Add nPowTargetSpacingV2 parameter for future compatibility
- Swap rule change activation threshold and miner confirmation window values
- Clarify fPowAllowMinDifficultyBlocks comment
The previous consensus parameters prevented the node from completing
initial sync without manually importing blocks. Updated chainparams so
a fresh node can fully synchronize on its own.
Update all references to 'testnet3' to 'testnet' for consistency. This includes:
- Changing magic bytes in network messages
- Updating directory paths and configuration files
- Modifying documentation and test framework references
- Adjusting chain parameters and validation logic
