keep pool in a locked state while activating, to prevent reentrancy

- Note that the pool is unlocked while executing the Uniswap activateHook function,
  but this only makes one external call to the (trusted) poolManager, and all the
  pool's invariants are already setup at that time.
- Spearbit #7

Author: hoytech

src/EulerSwapManagement.sol

@@ -64,7 +64,7 @@ contract EulerSwapManagement is EulerSwapBase {
         IEulerSwap.StaticParams memory sParams = CtxLib.getStaticParams();
 
         require(s.status == 0, AlreadyActivated());
-        s.status = 1;
+        s.status = 2; // Keep pool locked during activation
 
         // Static parameters
 
@@ -126,6 +126,8 @@ contract EulerSwapManagement is EulerSwapBase {
         ) {
             IEVC(evc).enableCollateral(sParams.eulerAccount, sParams.supplyVault1);
         }
+
+        s.status = 1; // unlock pool
     }
 
     function setManager(address manager, bool installed) external nonReentrant {