feat(examples): add SynapticChain Layer-1 ISO 20022 settlement connector

[Synaptics-Lab]

This PR adds a standalone pure Rust connector example demonstrating how Hyperswitch can route financial settlement transactions to SynapticChain Layer-1.

Key Capabilities:

• Native ISO 20022 pacs.008 XML message generation on Layer-1
• 256 parallel execution lanes eliminating Head-of-Line nonce blocking (ADR-062)
• Sub-500ms deterministic BFT finality for cross-border and regional payment corridors (cTZS, cKES, cNGN, sUSD)

Organization: https://github.com/Synaptics-Lab

Fixes #13910

[XyneSpaces]

[blocking] The new example imports synaptic_hyperswitch, but this crate/module is not present in the workspace and no dependency or [[example]] target is added. Running this example from the repo will fail to resolve the import, so please either add the real workspace crate/dependency and wire the example through Cargo or remove this standalone file until the connector code is included.

[XyneSpaces]

[should-fix] The new example is not wired to any Cargo package and references crates that are not declared in this workspace (synaptic_hyperswitch, and no owning package for the root examples/ directory). Please either add the package/dependency wiring needed for this example to compile, or move/remove it from the buildable examples surface.

[XyneSpaces]

[blocking] Please either add the synaptic_hyperswitch crate as a workspace dependency/example target or remove this example from the PR.

As added, examples/synaptic_hyperswitch_connector.rs imports synaptic_hyperswitch::{...} but the PR does not add that crate anywhere, so cargo check --examples/cargo run --example synaptic_hyperswitch_connector will fail before the demo can build.

[XyneSpaces]

[should-fix] Please either move this demo into a real Cargo package/example target with the required dependency, or remove/update the unresolved synaptic_hyperswitch import. The PR only adds examples/synaptic_hyperswitch_connector.rs, but the workspace members are crates/*, so this root-level example is not checked by CI and currently cannot compile due to the missing crate.

[XyneSpaces]

[should-fix] The added example is not buildable from this repo as-is: it imports synaptic_hyperswitch::{...} but this crate/module is not present in the repository and the PR does not add a Cargo manifest dependency or example package for it. Please either add the missing dependency/manifest wiring needed to compile the example, or remove the example until the connector crate exists.

[XyneSpaces]

[should-fix] Please either move examples/synaptic_hyperswitch_connector.rs under a real Cargo package with the required dependencies, or remove it from this PR. The root workspace has no [package] owning examples/, and the file imports synaptic_hyperswitch, which is not declared as a workspace member or dependency, so the demo has no working cargo run --example ... path.

[XyneSpaces]

[blocking] The added example is not runnable from this workspace: the root manifest is a virtual workspace with members limited to crates/*, so cargo run --example synaptic_hyperswitch_connector will not find this top-level example target. Please move it under an owning crate's examples/ directory or add an actual package/manifest wiring for it; otherwise the example also imports an undeclared synaptic_hyperswitch crate.

Affected lines include examples/synaptic_hyperswitch_connector.rs:5-9 and the new top-level examples/ file placement.

[XyneSpaces]

[should-fix] Please wire this demo into a Cargo package (or move it under an existing crate with the required dependencies) instead of adding it only under the workspace-root examples/ directory. The root Cargo.toml is a virtual workspace with only [workspace], so cargo run --example synaptic_hyperswitch_connector has no package/example target here and this file is not buildable as committed.