Add Spin adapter to public docs and README

- README Quick Start: add cargo test-spin
- README Development: replace broad workspace clippy with target-matched
  aliases and note why; add cargo test-spin to test list
- architecture.md: mention Cloudflare/Spin in the high-level overview;
  add trusted-server-adapter-spin section with build/test/lint commands
  and known MVP limits; expand Runtime Targets table to include all four
  adapters; add note on target-matched clippy requirement

Author: prk-Jr

README.md

@@ -34,6 +34,9 @@ cargo test-axum
 # Run tests (Cloudflare Workers adapter — native host)
 cargo test-cloudflare
 
+# Run tests (Spin adapter — native host)
+cargo test-spin
+
 # Start local server — Axum (no Fastly CLI or Viceroy required)
 cargo run -p trusted-server-adapter-axum
 
@@ -47,13 +50,19 @@ fastly compute serve
 # Format code
 cargo fmt
 
-# Lint
-cargo clippy --workspace --all-targets --all-features -- -D warnings
+# Lint — use target-matched aliases (workspace has multiple WASM runtimes;
+# broad --all-features clippy is not a reliable gate across adapters)
+cargo clippy-fastly
+cargo clippy-axum
+cargo clippy-cloudflare
+cargo clippy-spin-native
+cargo clippy-spin-wasm
 
 # Run all tests
 cargo test-fastly      # Fastly/WASM (requires Viceroy)
 cargo test-axum        # Axum native adapter
 cargo test-cloudflare  # Cloudflare Workers adapter (native host)
+cargo test-spin        # Spin adapter (native host)
 ```
 
 See [CONTRIBUTING.md](CONTRIBUTING.md) for contribution guidelines.

docs/guide/architecture.md

@@ -4,7 +4,7 @@ Understanding the architecture of Trusted Server.
 
 ## High-Level Overview
 
-Trusted Server is built as a Rust-based edge computing application. The core logic lives in a platform-agnostic library; platform-specific adapters target different runtimes (Fastly Compute, native Axum).
+Trusted Server is built as a Rust-based edge computing application. The core logic lives in a platform-agnostic library; platform-specific adapters target different runtimes (Fastly Compute, Cloudflare Workers, Fermyon Spin, native Axum).
 
 ```mermaid
 flowchart TD
@@ -61,6 +61,33 @@ Native Axum dev/test adapter (native binary):
 | Admin key management (`/admin/keys/*`) | Returns 501 Not Implemented                                                                                                                  |
 | Auction fan-out ordering               | Requests run concurrently via `tokio::spawn`; `select` returns first-to-complete but does not replicate Fastly's priority-queue tie-breaking |
 
+### trusted-server-adapter-spin
+
+Fermyon Spin adapter (`wasm32-wasip1` component):
+
+- Production-capable deployment target for the Spin runtime
+- Platform services (config store, secret store, KV) backed by Spin component variables and the EdgeZero KV handle
+- Outbound HTTP via `spin_sdk::http::send` — no configurable per-request timeout (see rustdoc)
+- Single auction provider only; multi-provider fan-out requires the Fastly adapter
+
+```bash
+# Check (native)
+cargo check -p trusted-server-adapter-spin
+
+# Check (WASM component target)
+cargo check-spin
+
+# Build WASM artifact
+cargo build --package trusted-server-adapter-spin --target wasm32-wasip1 --features spin --release
+
+# Test (native host)
+cargo test-spin
+
+# Lint
+cargo clippy-spin-native
+cargo clippy-spin-wasm
+```
+
 ## Design Patterns
 
 ### RequestWrapper Trait
@@ -124,12 +151,14 @@ User data is not persisted in storage - only processed in-flight at the edge.
 
 ## Runtime Targets
 
-| Adapter                         | Target          | Use case                                                          |
-| ------------------------------- | --------------- | ----------------------------------------------------------------- |
-| `trusted-server-adapter-fastly` | `wasm32-wasip1` | Production on Fastly Compute                                      |
-| `trusted-server-adapter-axum`   | native          | Local development and integration testing (see limitations above) |
+| Adapter                             | Target                    | Use case                                                          |
+| ----------------------------------- | ------------------------- | ----------------------------------------------------------------- |
+| `trusted-server-adapter-fastly`     | `wasm32-wasip1`           | Production on Fastly Compute                                      |
+| `trusted-server-adapter-cloudflare` | `wasm32-unknown-unknown`  | Production on Cloudflare Workers                                  |
+| `trusted-server-adapter-spin`       | `wasm32-wasip1` component | Production on Fermyon Spin                                        |
+| `trusted-server-adapter-axum`       | native                    | Local development and integration testing (see limitations above) |
 
-The Fastly adapter compiles to WebAssembly for sandboxed, low-cold-start edge execution. The Axum adapter is a standard native binary — no WASM toolchain required for local development.
+The workspace has multiple WASM runtimes with runtime-specific SDKs. Use target-matched clippy aliases (`cargo clippy-fastly`, `cargo clippy-spin-native`, etc.) rather than broad `--all-features` workspace clippy — the latter is not a reliable gate across adapters.
 
 ## Next Steps