Add presigned order posting APIs

[cyl19970726]

Summary

• Add TradingService.presignMarketOrder / presignLimitOrder to create signed payloads without posting.
• Add postPresignedOrder with single-use protection, existing CLOB result semantics, and presign latency telemetry.
• Export PresignedOrder, fingerprint, options, and wallet identity types.
• Add explicit wallet identity support for builder/Safe, EOA, and deposit-wallet modes.
• Add deposit-wallet/POLY_1271 identity handling: owner EOA signs, derived deposit wallet is maker/funder, and missing funder config is rejected instead of silently using the wrong maker.

Parent PR / Evidence

• Parent Earning Engine PR: https://github.com/cyl19970726/let-me-try/pull/75
• Parent branch pins this submodule through commit 726bde3.
• Real-order evidence in the parent PR covers builder/Safe FAK and FOK successful fills, plus blocked/no-spend EOA and deposit-wallet probes that prove the code path reaches CLOB but the selected account lacks the required balance/approval readiness.

Tests

• npm exec --yes pnpm@9 -- --filter @catalyst-team/poly-sdk test -- src/__tests__/unit/trading-service-presign.test.ts → 5 tests passed.
• npm exec --yes pnpm@9 -- --filter @catalyst-team/poly-sdk build