refactor(ledger): expose the Ledger signers in a typed starknet/ledge…

[PhilippeR26]

Motivation and Resolution

The Ledger transport was typed as any (type _Transport = any): @ledgerhq/hw-transport was removed from the dependencies in 2024, after a packaging bug (LedgerHQ/ledger-live#7448). Importing the Ledger Transport type into the single dist/index.d.ts would break every project that does not use a Ledger and compiles with skipLibCheck: false (TS2307).

This PR adds a starknet/ledger entry point, with its own types file. There, the transport is typed with the Ledger Transport class. Nothing breaks in v11: the exports of starknet stay, deprecated. In v12, the code moves to src/ledger/ and these exports are removed.

RPC version (if applicable)

Not applicable.

Usage related changes

• New entry point starknet/ledger: LedgerSigner111, LedgerSigner221, LedgerSigner231, getLedgerPathBuffer111, getLedgerPathBuffer221, and the aliases LedgerSigner and getLedgerPathBuffer.

  import { LedgerSigner231 } from 'starknet/ledger'; // was imported from 'starknet'

• With this import, transporter has the type of the transport you pass (it was any for 221 and 231), and a value that is not a Ledger transport is refused at compile time.
• Importing them from starknet still works, but is marked @deprecated (removed in v12).
• @ledgerhq/hw-transport is an optional peer dependency (^6.0.0). The Ledger transport packages already install it. Projects without a Ledger see no change and no install warning (checked with npm, pnpm and yarn 1).
• Docs: API pages for starknet/ledger; the signature and migration guides use the new import. Ledger Starknet APP support is stated from v2.3.1 to v2.4.3 (tested on a device with v2.4.3).

Development related changes

• tsup builds a second entry point to dist/ledger/index.{js,mjs,d.ts}, with starknet kept external. The IIFE build keeps the main entry only and the ESM build has no shared chunk, so dist/index.js, dist/index.mjs and dist/index.global.js are unchanged except for comments (compared with a build of develop).
• tsconfig.json (paths) and both Jest configs (moduleNameMapper) map starknet to src/index.ts. An ESLint rule forbids importing starknet in src outside src/ledger.
• New unit test __tests__/utils/ledgerSigner.test.ts (no node needed).
• Docusaurus: a second docusaurus-plugin-typedoc instance writes to docs/API/ledger/, so the addresses of the existing API pages do not change; new sidebar category.
• Checked on the packed package: install with npm, pnpm and yarn 1; CJS and ESM imports; types with moduleResolution bundler, node16 and node.

Checklist:

• Performed a self-review of the code
• Rebased to the last commit of the target branch (or merged it into my branch)
• Documented the changes in code (API docs will be generated automatically)
• Updated the tests
• All tests are passing