Fermyon Spin entry point #732

Description

New trusted-server-adapter-spin crate. Entry point using #[http_component] and edgezero_adapter_spin::run_app(). Construct RuntimeServices with Spin-backed trait implementations (SpinConfigStore, SpinKvStore, SpinSecretStore, SpinProxyClient). Admin key routes. CI jobs for native + wasm32-wasip1 targets.

Notes

• Spin target is wasm32-wasip1 (same as Fastly) — WASI clock support is present, so std::time::Instant likely works. Audit auction/orchestrator.rs and proxy.rs before assuming no cleanup is needed.
• Client geo/IP is extracted from Spin-specific headers (spin-client-addr, spin-full-url) via SpinRequestContext, not a runtime context object.
• EdgeZero Spin adapter is Preview status — validate behavior of SpinConfigStore, SpinKvStore, and SpinSecretStore against the edgezero-adapter-spin crate.
• Add spin.toml configuration file analogous to cloudflare.toml.

Done when

• Route parity + basic-auth gate tests pass (native host target)
• Admin key routes work
• Crate host-compilable (cfg-gated shims for wasm32-only APIs)
• Spin CI jobs added (native compile-check + wasm32-wasip1 build)
• spin.toml present and valid
• Per-PR gates pass

Blocked by

PR 15 (#496)

References

• docs/internal/EDGEZERO_MIGRATION.md — Phase 4
• edgezero-adapter-spin — https://github.com/stackpop/edgezero
• Part of EdgeZero Integration #480