docs: resync skills with smg HEAD (v1.6.0)

[slin1237]

Summary

Skills were last verified against smg on 2026-06-17; ~103 commits have landed since (HEAD 72ec2bfa, 2026-07-15). Audited every recipe against the current code (not commit messages) via parallel per-subsystem audits and fixed the drift. 15 files changed, 23 confirmed drifts plus one architecture-coverage addition.

Highlights

Routing policies (9 → 10, passthrough added) — rippled through map/SKILL.md (×2), routing-policy.md, bindings-update.md (PolicyType/PolicyConfig).

gRPC router refactor (#1923) — documented the unified Mode-parameterized GrpcRouter + RequestPipeline/PipelineStage architecture in grpc-backend.md (pd_router.rs removed, epd_encode → common/stages/encode.rs), and added the TokenSpeedEncoderClient EPD-encode exception. This was a coverage gap, not a wrong claim — the recipes never described the router internals.

Factual fixes

• multimodal: drop non-existent ::new_dynamic (::new is generic over dimensionality); add AudioUrl/AudioData to MediaContentPart; scope the registry-ordering rule to the spec Vec (processor registry is a HashMap); fetch_video → Arc<VideoClip>.
• mcp: rmcp 0.8.x → 1.7; SSE client transport dropped — model new transports on the Streamable arm; drop SseClientTransport from the anti-pattern.
• rate-limit: rate_limit_tokens_per_second = 0 does not yield semaphore mode — coerced to max_concurrent_requests via .filter(|&t| t > 0).
• discovery: add the Encode pod type / --encode-selector; Router is an is_router overlay, not a PodType.
• provider-api: ProviderType gains Custom(String).
• config-plumbing: to_server_config does take a RouterConfig and uses .or_else() for discovery-derived fields.
• implement: realtime router path → routers/common/realtime/.
• wasm: OnError attach point is defined but not implemented.
• auth: JTI replay check is opt-in / off by default.
• storage-backend: data-connector v2.3.0 → v2.3.2.
• review-pr: correct the e2e pytest marker set (model/workers/gateway/e2e/slow).
• map: add the mm_rdma (smg-mm-rdma) crate row; fix the bindings param anchor.

Verified in sync (no changes)

scheduler, tenancy, tool-parser, reasoning-parser, observability, kv-index, mesh, contribute gate, review anti-patterns. Counts re-confirmed: 14 tool parsers, 8 reasoning families, Python Router now 117 params.

Known non-changes (flagged, not drift)

1. contribute/SKILL.md uses clippy --workspace; review-pr/CONTRIBUTING.md don't — both valid per their respective sources, just internally inconsistent.
2. contribute/SKILL.md documents no branch-name regex — a coverage gap; the enforced patterns live in the pre-commit branch-name-check hook and pr-naming-check.yml.