contracts: the contract engine, in the kit and its wasm build

.github/workflows/cont_integration.yml

@@ -39,6 +39,23 @@ jobs:
       - run: "cargo test -p lwk_wollet --lib --no-default-features --features ark ark::"
       - run: cargo test -p lwk_wollet --no-default-features --features ark --test ark_regtest --no-run
 
+  # The contract engine: every golden vector and refusal of the templates it
+  # carries, and the budget rule. The regtest drip needs a sequentiad binary,
+  # so it is built here, not run; the wasm bindings are checked for wasm32.
+  contracts:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/[email protected]
+        with:
+          targets: wasm32-unknown-unknown
+      - run: sudo apt-get update && sudo apt-get install -y libudev-dev clang llvm
+      - run: cargo test -p lwk_contracts
+      - run: cargo check -p lwk_wasm --target wasm32-unknown-unknown
+        env:
+          CC_wasm32_unknown_unknown: clang
+          AR_wasm32_unknown_unknown: llvm-ar
+
   nix:
     runs-on: ubuntu-22.04
     steps:

CLAUDE.md

@@ -41,10 +41,15 @@ fail; treat those as expected fork behaviour rather than as something you broke.
 ## The WASM build, and who consumes it
 
 ```sh
-cd lwk_wasm
-wasm-pack build --target web --release      # needs clang for the secp256k1 build
+lwk_wasm/build-web.sh                        # wasm-pack build --target web --release, paths remapped
 ```
 
+The script remaps every build-machine path (home directory, checkout, cargo
+caches) out of the `.wasm` and fails if one remains: a plain `wasm-pack
+build` embeds them in panic locations, so the published file would name this
+machine and differ from a build made elsewhere. It needs clang with a wasm32
+backend, for the secp256k1 and Simplicity C libraries.
+
 `--target web` is not optional. The output lands in `lwk_wasm/pkg/` (gitignored, never committed)
 and is consumed by
 [`sequentia-web-wallet`](https://github.com/ConcatenaLabs/sequentia-web-wallet),