refactor(clientversion): simplify version string formatting

Replace direct CLIENT_BUILD usage with FormatVersion to consistently display semantic versioning. This omits trailing ".0" and git suffix when build number is zero, making version strings cleaner and more predictable.

src/clientversion.cpp

@@ -79,7 +79,11 @@ static std::string FormatVersion(int nVersion)
 
 std::string FormatFullVersion()
 {
-    return CLIENT_BUILD;
+    // Display a simplified semantic version: omit trailing ".0" and git suffix
+    // by reusing FormatVersion on the aggregated CLIENT_VERSION.
+    // This yields e.g. "v1.4.1" when CLIENT_VERSION_BUILD == 0,
+    // or "v1.4.1.1" if a non-zero build number is used.
+    return std::string("v") + FormatVersion(CLIENT_VERSION);
 }
 
 /**