Convert to npm

[peachbits]

Note

Low Risk
Dev/CI and documentation only; no runtime or currency plugin logic changes.

Overview
This PR migrates the repo from Yarn to npm as the primary package manager.

Tooling: Adds .npmrc with legacy-peer-deps=true and ignore-scripts=true (replacing the old .yarnrc ignore-scripts setting). Removes .yarnrc and stops ignoring package-lock.json in .gitignore so the lockfile is tracked. CI on Travis now runs npm run verify instead of yarn verify.

Docs: README.md and docs/currency-integration.md tell contributors to use npm run start for the Webpack dev server instead of yarn start.

^{Reviewed by Cursor Bugbot for commit 332e586. Bugbot is set up for automated code reviews on this repo. Configure here.}

[j0ntz]

CI status: Travis is red, failing at the test step of verify (prepare/lint/types pass; Bugbot is clean). Verified from the build log:

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" — test/common/fees/calcMinerFeePerByte.spec.ts

Same root cause as EdgeApp/disklet#45 — after the npm conversion mocha isn't loading the TypeScript register, so .ts specs can't be imported. The mocha .ts loader needs wiring up.

[j0ntz]

Applied in 332e586. Pinned get-func-name to 2.0.2 via npm overrides. The lock had resolved the broken ESM-only get-func-name@2.0.1, which chai (CommonJS) can't require → mocha falls back to import() of the .ts specs → ERR_UNKNOWN_FILE_EXTENSION. Verified on Node 18 (matching this PR's CI): npm ci in sync + npm run verify green (1215 passing). Flagging since this is my change on your branch — please review.