fix(verify): build the conformance adapter on Express 5 / Node 24

[Bccorb]

Root cause

Conformance CI (conformance workflow → seamless verify --local) has been failing on every branch since the ecosystem upgraded to Node 24. The failure is not the Node image version — it's an npm peer-dependency conflict.

The verify harness's adapter app (verify/adapter-app) pinned express@^4.19.2. On the server repo's default branch, @seamless-auth/express@0.8.0 now declares:

peerDependencies: { "express": ">=5.0.0", "@types/express": ">=5.0.0" }
engines:          { "node": ">=24 <25" }

In --local mode the SDK is built from source and packed into a tarball, then installed over the adapter's deps. Installing @seamless-auth/express (peer express@>=5) on top of Express 4 aborts with ERESOLVE, which fails the adapter Docker build, cancels the whole compose build, and makes seamless verify exit 1.

From the failing run:

npm error ERESOLVE unable to resolve dependency tree
npm error Found: express@4.22.2  (express@"^4.19.2" from the root project)
npm error Could not resolve dependency:
npm error peer express@">=5.0.0" from @seamless-auth/express@0.8.0
target adapter: failed to solve: ... exit code: 1

Fix

• verify/adapter-app/package.json: express@^4.19.2 → ^5.1.0, @seamless-auth/express@^0.6.0 → ^0.8.0.
• Bump the verify Docker images node:20 → node:24 (adapter Dockerfile + the react service's inline Dockerfile) to match the ecosystem's supported runtime (node >=24 <25).

server.mjs already uses only Express 5-safe APIs (named :email param, no wildcard routes, no removed app.del/req.param), so no code changes were needed there.

Validation

Reproduced the exact adapter install locally against freshly-packed SDK tarballs from the server repo:

• Old config (express@^4.19.2): reproduces the CI ERESOLVE failure. ✅ confirmed the root cause.
• New config (express@^5.1.0): SDK tarballs install cleanly (resolves express@5.2.1), the adapter boots (verify adapter listening), and GET / + the GET /__captured/:email route both respond correctly.

Repo test suite: 552 passed. A patch changeset is included (the verify/ dir ships in the package files).

Note: this is independent of and separate from the recently added seamless login --local mode.