phase 20f: vsomeip-based SD-conformance test (POC, #[ignore]'d)

[JustinKovacich]

First test in the simple-someip crate that catches protocol non-compliance bugs against an external SOME/IP-SD reference (the COVESA vsomeip implementation), rather than running our own impl on both sides of the wire and only catching internal- consistency issues.

Scope: single SD OfferService reception. simple-someip's Client::bind_discovery() listens for vsomeip's announcement of a known service+instance pair, asserts the SD entry surfaces on the update stream within a 30 s timeout. That single signal is the load-bearing wire-conformance check we have zero of today. Subsequent phases will layer Subscribe/Ack roundtrips, request/response, E2E protect/check, etc. against the same reference.

#[ignore]'d by default. The test depends on an external vsomeip Docker container being up — see the test file's module-level docs for the docker setup, the JSON config to mount, and the env-var (SIMPLE_SOMEIP_TEST_INTERFACE) to point at the test's listening interface. Phase 20g will wire this into CI via TestContainers-rs (or similar) once the manual setup is proven.

Why ignored not a CI step yet:

Per FW team confirmation, vsomeip-in-docker on CI is approved-in-principle but not yet stood up. Shipping the test infrastructure first lets the firmware team pick up the test locally for debugging during the codec-MVP integration; CI automation lands as 20g.

Cleanup folded in: clippy warnings surfaced under broader feature combos (--features client-tokio,server-tokio) by prior phases:

• event_publisher.rs:57 doc-markdown PhantomData now backticked.
• event_publisher.rs:670/732 clippy::type_complexity #[allow(...)]'d on the test type aliases (with reason string explaining why).
• server/mod.rs:929 doc-markdown TokioSocket now backticked.
• sd_state.rs Default impl added on SdStateManager (clippy::pedantic; bare-metal callers should still prefer the explicit const new() for static initializers).

Default-features cargo clippy --tests had only 2 pre-existing warnings before this commit and still has only 2 after; no new warnings on the canonical CI gate. The broader-feature warnings were a 20e-introduced side-effect.

Gates green:

• cargo fmt --check
• cargo clippy --tests (default features; 2 pre-existing warnings unrelated to this work)
• cargo build --workspace --all-targets
• cargo build --no-default-features --features client,server,bare_metal
• cargo build -p simple-someip-embassy-net --target thumbv7em-none-eabihf
• cargo test --features client-tokio,server-tokio --test client_server -- --test-threads=1 (11/11)
• cargo test --features client,server,bare_metal --test bare_metal_e2e (2/2)
• cargo test -p simple-someip-embassy-net --test loopback (3/3)
• cargo test --features client-tokio,server-tokio --test vsomeip_sd_compat (1 ignored as expected)

What this leaves for 20g:

• tests/data/vsomeip-offerer/Dockerfile building vsomeip from source.
• TestContainers-rs (or equivalent) integration so cargo test --features client-tokio,server-tokio --test vsomeip_sd_compat -- --ignored works in a CI runner with Docker available.
• vsomeip version pin matching whatever the FW team selects for production validation.
• Subsequent conformance tests: Subscribe/Ack, request/response, E2E roundtrips.

[Copilot]

Pull request overview

Adds an initial (ignored-by-default) integration test to validate SOME/IP-SD OfferService reception against an external reference implementation (COVESA vsomeip), plus a few clippy/doc cleanups and a Default impl for SD state management.

Changes:

• Add tests/vsomeip_sd_compat.rs: ignored conformance test that waits for vsomeip’s OfferService to appear on Client’s discovery update stream.
• Add Default for SdStateManager (delegating to the existing const fn new()).
• Doc/clippy hygiene: backtick code identifiers in docs; suppress clippy::type_complexity on verbose test-local types.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tests/vsomeip_sd_compat.rs	New ignored vsomeip-based SD conformance test + detailed local-run instructions/config snippet.
src/server/sd_state.rs	Adds Default impl for SdStateManager (delegates to new()).
src/server/mod.rs	Doc comment: backtick TokioSocket.
src/server/event_publisher.rs	Doc comment: backtick PhantomData; clippy suppression for complex test types.

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[Copilot]

The sample vsomeip-offerer.json sets "multicast": "224.0.23.0", but the client listens on crate::protocol::sd::MULTICAST_IP (239.255.0.255). Unless vsomeip is configured to match the same group, bind_discovery() won’t receive any SD traffic. Align this JSON snippet with the crate’s multicast constant (or document how to override the client’s multicast group if supported).

[Copilot]

Unlike other feature-gated integration tests in this repo (e.g. client_server, bare_metal_*), this test isn’t registered in Cargo.toml with [[test]] required-features = ["client-tokio", "server-tokio"]. With only the in-file #![cfg(...)], cargo test --test vsomeip_sd_compat can succeed with “0 tests” when the features aren’t enabled, which is confusing for users following the module docs. Consider adding the [[test]] required-features entry (and optionally keeping this #![cfg] as a belt-and-suspenders guard).

[Copilot]

The module docs and sample docker run instructions reference SD multicast 224.0.23.0, but this crate’s SD implementation joins crate::protocol::sd::MULTICAST_IP which is 239.255.0.255 (see src/protocol/sd/mod.rs). As written, following these instructions will configure vsomeip to announce on a different multicast group than the client listens to, so the test will never observe OfferService. Update the docs/config snippets to use 239.255.0.255 (or make the client’s SD multicast group configurable and document that instead).

Suggested change

	//! the container in host-network mode so SD multicast (224.0.23.0)
	//! the container in host-network mode so SD multicast (239.255.0.255)