Wire Taproot script verification into validation/policy/libconsensus and update standardness flags.
Adapt wallet_multiwallet functional test to match filesystem error variants (create_directory/create_directories/filesystem error), making the suite robust across fs backends and library versions.
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
