test V5 sentinel + min sentinels through IFlowV5 re-export

test/interface/IFlowV5.t.sol

@@ -4,13 +4,25 @@ pragma solidity =0.8.25;
 
 import {Test} from "forge-std/Test.sol";
 
-import {RAIN_FLOW_SENTINEL} from "../../src/interface/deprecated/v4/IFlowV4.sol";
+import {RAIN_FLOW_SENTINEL, MIN_FLOW_SENTINELS} from "../../src/interface/IFlowV5.sol";
 import {Sentinel} from "rain.solmem/lib/LibStackSentinel.sol";
 
 contract IFlowV5Test is Test {
+    /// `IFlowV5` re-exports `RAIN_FLOW_SENTINEL` from `IFlowV4`. This pins the
+    /// value through the V5 re-export surface so a change to the V5 re-export
+    /// (intentional or accidental) is caught here, not silently passed through
+    /// by importing the V4 constant directly.
     function testSentinelValue() external {
         assertEq(
             0xfea74d0c9bf4a3c28f0dd0674db22a3d7f8bf259c56af19f4ac1e735b156974f, Sentinel.unwrap(RAIN_FLOW_SENTINEL)
         );
     }
+
+    /// `IFlowV5` also re-exports `MIN_FLOW_SENTINELS`. The three required
+    /// sentinels (ERC20, ERC721, ERC1155 sections) make this `3`. Pinning it
+    /// through the V5 interface guards the re-export the same way as the
+    /// sentinel value above.
+    function testMinFlowSentinelsValue() external {
+        assertEq(MIN_FLOW_SENTINELS, 3);
+    }
 }