fix(explicabl): drop undeclared node-fetch import; use global fetch

[davidcrowe]

Problem

@gatewaystack/[email protected] is broken on fresh install — the same defect class as the proxyabl-core/jose break in #35.

src/health.ts:2 does import fetch from "node-fetch", but the package declares only express and express-rate-limit. Since dist/index.js re-exports health.js, every import of the package fails:

npm install @gatewaystack/explicabl
node -e "import('@gatewaystack/explicabl')"
# ERR_MODULE_NOT_FOUND: Cannot find package 'node-fetch'

This hits users who only want createConsoleLogger or explicablLoggingMiddleware and never touch the health route. It also contradicts the README's "Zero dependencies beyond Express" (line 20).

Fix

The two call sites (health.ts:73, :86) use only standard WHATWG fetch (.ok, .status, {method, headers, body}) — a drop-in for Node 18+'s global fetch. So: delete the import, add engines.node >=18 to make the requirement explicit, bump to 0.0.9. Declaring node-fetch would also fix the crash, but it's dead weight on modern Node and would keep the README claim false.

Verification

• Packed the fixed tarball, installed into an empty project, imported → succeeds with all 5 exports (auth0LogsWebhook, createConsoleLogger, explicablLoggingMiddleware, explicablRouter, healthRoutes)
• Full suite: 17 files / 159 tests green
• Published 0.0.8 independently reproduced as failing from the registry

Needs a republish after merge (0.0.9).

[davidcrowe]

Reviewed + confirmed green (build + test SUCCESS, MERGEABLE/CLEAN). Drops the undeclared node-fetch import for global fetch (Node 18+, backed by the new engines: node>=18) — correct, fixes the fresh-install break.

@davidcrowe — needs your merge + republish (OTP): [email protected].