Add override_state_values support to initialize_from

[Smitaambiger]

@skrawcz Related to #416

This PR adds an optional override_state_values parameter to ApplicationBuilder.initialize_from, allowing callers to override or augment state values when initializing from a persisted state.

Changes

• Added override_state_values parameter to initialize_from
• Stored override values on the builder
• Applied overrides after persisted state is loaded

How I tested this

• Reviewed the state initialization and persistence flow
• Verified that override values are applied after loading persisted state
• Confirmed existing behavior is unchanged when overrides are not provided

Notes

This change is backward-compatible and only applies when
override_state_values is explicitly passed.