refactor(build): enable Wasm by default and refactor modules for improved KMP compatibility

Enabled Wasm target across all relevant modules and removed conditional enablement logic. Refactored `core:core-utils` to move JVM-specific code to a new `backend:infrastructure:persistence` module for strict KMP compliance. Updated dependencies, adjusted Gradle configurations, and resolved circular dependencies.

frontend/core/navigation/build.gradle.kts

@@ -11,7 +11,6 @@ version = "1.0.0"
 
 kotlin {
   // Toolchain is now handled centrally in the root build.gradle.kts
-  val enableWasm = providers.gradleProperty("enableWasm").orNull == "true"
 
   jvm()
 
@@ -25,11 +24,10 @@ kotlin {
     }
   }
 
-  if (enableWasm) {
-    @OptIn(org.jetbrains.kotlin.gradle.ExperimentalWasmDsl::class)
-    wasmJs {
-      browser()
-    }
+  // Wasm enabled by default
+  @OptIn(org.jetbrains.kotlin.gradle.ExperimentalWasmDsl::class)
+  wasmJs {
+    browser()
   }
 
   sourceSets {