fix(runtime): add missing buildRouteName utility function

Adds the buildRouteName() utility function that was referenced by generated
code but was missing from the runtime library.

This function creates unique route names for the Compose Navigation library
by combining the entry's qualified class name with a hash of its arguments
(if present).

Fixes compilation errors in generated entry factory code.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: kikin81

nibel-runtime/src/main/kotlin/nibel/runtime/RouteBuilder.kt

@@ -0,0 +1,22 @@
+package nibel.runtime
+
+import android.os.Parcelable
+
+/**
+ * Builds a unique route name for navigation based on the entry class name and arguments.
+ *
+ * The route name is used by the Compose Navigation library to identify destinations.
+ * For entries with arguments, the route includes a hash of the arguments to ensure uniqueness.
+ * For entries without arguments, only the qualified name is used.
+ *
+ * @param qualifiedName The fully qualified class name of the entry
+ * @param args The arguments for the entry, or null if no arguments
+ * @return A unique route string for navigation
+ */
+fun buildRouteName(qualifiedName: String, args: Parcelable?): String {
+    return if (args != null) {
+        "$qualifiedName@${args.hashCode()}"
+    } else {
+        qualifiedName
+    }
+}