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.
Removed redundant `jvmToolchain(25)` declarations across module build scripts, as the JVM toolchain is now managed centrally. Added comments for clarity.
