feat(paymaster): add separate whitelistAdmin param to BondTreasuryPaymaster

[aliXsed]

Summary

The BondTreasuryPaymaster constructor previously coupled DEFAULT_ADMIN_ROLE and WHITELIST_ADMIN_ROLE to the same admin address. This made it impossible to assign whitelist management to an operational key (e.g. FLEET_OPERATOR) while keeping DEFAULT_ADMIN_ROLE on a multisig at deployment time.

Changes

• BondTreasuryPaymaster.sol: Add whitelistAdmin as a new constructor parameter (2nd position). When whitelistAdmin != admin, the constructor grants WHITELIST_ADMIN_ROLE to whitelistAdmin in addition to admin.
• DeploySwarmUpgradeableZkSync.s.sol: Pass fleetOperator as whitelistAdmin so the fleet operator gets WHITELIST_ADMIN_ROLE and NODL_ADMIN retains DEFAULT_ADMIN_ROLE.
• BondTreasuryPaymaster.t.sol: Update MockBondTreasuryPaymaster and all test instantiations. Add test_separateWhitelistAdmin to verify role separation.
• swarm-specification.md: Update deployment example.

Motivation

During the ZkSync mainnet deployment, we discovered that the single admin parameter forced FLEET_OPERATOR to receive DEFAULT_ADMIN_ROLE (a security risk) or NODL_ADMIN to receive WHITELIST_ADMIN_ROLE (operationally impractical since it's a multisig). This fix allows proper separation of concerns at deployment time.

Testing

All 55 BondTreasuryPaymasterTest tests pass.

[github-actions]

LCOV of commit 4ea1d77 during checks #640

Summary coverage rate:
  lines......: 32.1% (769 of 2392 lines)
  functions..: 28.9% (108 of 374 functions)
  branches...: 37.7% (139 of 369 branches)

Files changed coverage rate:
                                                  |Lines       |Functions  |Branches    
  Filename                                        |Rate     Num|Rate    Num|Rate     Num
  ======================================================================================
  script/DeploySwarmUpgradeableZkSync.s.sol       | 0.0%     64| 0.0%     1|    -      0
  src/paymasters/BondTreasuryPaymaster.sol        | 0.0%     30| 0.0%     3| 0.0%      7
  test/paymasters/BondTreasuryPaymaster.t.sol     | 0.0%     12| 0.0%     5|    -      0