Add stake on behalf of account functionality

.gitignore

@@ -10,3 +10,4 @@ artifacts/
 .vscode
 typechain-types
 scripts/safe/*.json
+scripts/deployStakingRewards/*testnet*.json

README.md

@@ -189,4 +189,4 @@ All upgrades go through the Timelock (2-day minimum delay):
 
 ## Security Audits
 1. [HALBORN](https://www.halborn.com/audits) has performed a security audit of `BillionsNetworkToken` smart contract and compiled report on Dec 5, 2025: [billions-token-7661d8](https://github.com/BillionsNetwork/billions-token/blob/main/audits/Billions_Token_SSC.pdf).  
-2. [HALBORN](https://www.halborn.com/audits) has performed a security audit of `StakingRewards` smart contract and compiled report on Jan 5, 2026: [staking-rewards-0b472f](https://github.com/BillionsNetwork/billions-token/blob/main/audits/Staking_Rewards_SSC.pdf).
+2. [HALBORN](https://www.halborn.com/audits) has performed a security audit of `StakingRewards` smart contract and compiled report on Jan 5, 2026: [staking-rewards-0b472f](https://github.com/BillionsNetwork/billions-token/blob/main/audits/Staking_Rewards_SSC.pdf).

contracts/staking/interfaces/IStakingRewards.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+pragma solidity 0.8.30;
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 
@@ -8,7 +8,7 @@
  * @notice Interface for the StakingRewards contract
  * @dev Based on Synthetix StakingRewards with token locking support
  */
 interface IStakingRewards {
     /* ========== STRUCTS ========== */
 
     struct LockedStake {
@@ -19,7 +19,7 @@
 
     /* ========== VIEWS ========== */
 
     function rewardsToken() external view returns (IERC20);
 
     function stakingToken() external view returns (IERC20);
 
@@ -33,10 +33,12 @@
 
     function rewardPerTokenStored() external view returns (uint256);
 
-    function rewardsDistribution() external view returns (address);
-
     function userRewardPerTokenPaid(address account) external view returns (uint256);
 
+    function initialLockPeriodFinish() external view returns (uint256);
+
+    function initialLockPeriodDuration() external view returns (uint256);
+
     function rewards(address account) external view returns (uint256);
 
     function totalSupply() external view returns (uint256);
@@ -61,6 +63,8 @@
 
     function stake(uint256 amount) external;
 
+    function stakeOnBehalf(address account, uint256 amount) external;
+
     function withdraw(uint256 amount) external;
 
     function lockStake(uint256 amount, uint256 lockDuration) external;
@@ -71,6 +75,8 @@
         uint256 lockDuration
     ) external;
 
+    function stakeAndLockOnBehalf(address account, uint256 amount, uint256 lockDuration) external;
+
     function getReward() external;
 
     function exit() external;
@@ -79,13 +85,24 @@
 
     function notifyRewardAmount(uint256 reward) external;
 
-    function setRewardsDistribution(address _rewardsDistribution) external;
-
     function recoverERC20(address tokenAddress, uint256 tokenAmount) external;
 
     function setRewardsDuration(uint256 _rewardsDuration) external;
 
     function pause() external;
 
     function unpause() external;
+
+    function setInitialLockPeriod(uint256 duration) external;
+
+    /* ========== EVENTS ========== */
+
+    event RewardAdded(uint256 reward);
+    event Staked(address indexed user, uint256 amount);
+    event Withdrawn(address indexed user, uint256 amount);
+    event RewardPaid(address indexed user, uint256 reward);
+    event RewardsDurationUpdated(uint256 newDuration);
+    event Recovered(address token, uint256 amount);
+    event StakeLocked(address indexed user, uint256 amount, uint256 lockDuration);
+    event InitialLockPeriodUpdated(uint256 newDuration);
 }