fix: correct _majorVersion() to extract full major version component

src/contracts/mixins/SemVerMixin.sol

@@ -33,6 +33,25 @@ abstract contract SemVerMixin is ISemVerMixin {
     /// @return The major version string (e.g., "1" for version "1.2.3")
     function _majorVersion() internal view returns (string memory) {
         bytes memory v = bytes(_VERSION.toString());
-        return string(abi.encodePacked(v[0]));
+        uint256 start;
+
+        // Skip optional 'v'/'V' prefix to keep only the numeric major component.
+        if (v.length > 0 && (v[0] == 0x76 || v[0] == 0x56)) {
+            start = 1;
+        }
+
+        uint256 end = start;
+        while (end < v.length && v[end] != 0x2e) {
+            unchecked {
+                ++end;
+            }
+        }
+
+        bytes memory major = new bytes(end - start);
+        for (uint256 i = start; i < end; ++i) {
+            major[i - start] = v[i];
+        }
+
+        return string(major);
     }
 }