Add sdk-lite API contract tests

[MyouzzZ]

Closes #48

Summary

• add a shared API contract fixture for the current access API endpoints
• expand sdk-lite to cover membership lookup, member profile lookup, access checks, and community member listing
• add sdk-lite contract tests that assert request paths, methods, payloads, and parsed responses against the shared fixture
• make access-api route integration tests consume the same fixture so route samples and sdk-lite expectations cannot silently drift
• fix existing local validation blockers in the access-api Prisma schema and seed flow so affected tests can run

Validation

• corepack pnpm --filter @guildpass/sdk-lite test (16 tests)
• corepack pnpm --filter @guildpass/sdk-lite build
• corepack pnpm --filter @guildpass/shared-types typecheck
• corepack pnpm --filter access-api prisma:generate
• corepack pnpm --filter access-api test (14 tests)

Notes

• corepack pnpm test still fails in the pre-existing @guildpass/policy-engine workspace due unresolved @guildpass/shared-types resolution/test-helper errors outside this PR touched area.