refactor(N-01): emit PoolTotalsUpdated in _unstake, reserve ExchangeRateUpdated for fee distribution only

Author: mzhakun

src/RNBWStaking.sol

@@ -704,6 +704,7 @@ contract RNBWStaking is IRNBWStaking, ReentrancyGuard, Pausable, EIP712 {
 
         // 10. Emit events
         emit Unstaked(user, sharesToBurn, rnbwValue, exitFee, netAmount);
+        emit PoolTotalsUpdated(totalPooledRnbw, totalShares);
     }
 
     /// @dev Stakes from the pre-funded staking reserve — no token transfer,

src/interfaces/IRNBWStaking.sol

@@ -59,9 +59,8 @@ interface IRNBWStaking {
     /// @param totalShares The total shares outstanding
     event ExchangeRateUpdated(uint256 totalPooledRnbw, uint256 totalShares);
 
-    /// @notice Emitted after stake or cashback allocation — both totalPooledRnbw and totalShares
-    ///         increase proportionally, so the exchange rate stays ~constant (modulo rounding dust).
-    ///         Use ExchangeRateUpdated to track actual rate changes (unstake, fee distribution).
+    /// @notice Emitted after stake, unstake, or cashback allocation — pool totals change but
+    ///         the exchange rate stays ~constant (both sides scale proportionally, modulo rounding dust).
     /// @param totalPooledRnbw The total RNBW in the staking pool
     /// @param totalShares The total shares outstanding
     event PoolTotalsUpdated(uint256 totalPooledRnbw, uint256 totalShares);