[GF-08] [BACKEND] TypeScript SDK: Full Implementation + Tests

[bellabuks]

Summary

Implements all stub methods in the TypeScript SDK and adds a full test suite.

• deposit - converts USDC string to stroops (7-decimal precision), enforces per-tier minimum deposits, throws BelowMinDepositError for amounts below minimums; delegates to simulateThenSubmit
• withdraw - submits invocation and translates contract lock errors into LockNotExpiredError
• earlyExit - runs simulation first to provide a fee preview, then submits
• position - queries all four tiers in parallel, returns the first active position
• Tests - added src/__tests__/index.test.ts with Vitest covering success paths, error cases, call-order verification, and fallback behaviour
• CI fix - updated .github/workflows/ci.yml SDK job to run pnpm build and pnpm test after typecheck, generating the required dist/ artifacts; switched install to pnpm install to allow lock-file refresh when dependencies change
• package.json - added vitest to devDependencies and a test script

closes #41

[vercel]

@bellabuks is attempting to deploy a commit to the wumibals' projects Team on Vercel.

A member of the Team first needs to authorize it.

[Leothosine]

This is perfect