Potentially use whck from bin/ folder for symlinks to existing installs outside of $PATH (from PHP PoV)

bin/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

index.php

@@ -97,9 +97,11 @@ function verify_claim(string $payload, string $claim, string $id, string $valida
 function find_whck() {
     // BUG: https://bugs.php.net/bug.php?id=77782
     // $_ENV['whck'] and getenv("whck") are empty, but getenv()["whck"] works!
+    // NOTE: We use is_file not file_exists() because there may be a whck/ folder
+    // In that case, we check for bin/whck
     return isset(getenv()['WHCK']) ? getenv()['WHCK'] // from $ENV
-        : (file_exists('whck') ? './whck' // from current directory
-            : 'whck');
+        : (is_file('whck') ? './whck' // from current directory
+            : (is_file('bin/whck') ? 'bin/whck' : 'whck'));
 }
 
 //enum Validator {