fix: validate order identifiers and test public position flows

[kartojal]

Reject ambiguous or malformed order identifiers at runtime before metadata requests or signing. Inputs such as { tokenID: "123", positionID: null }, both IDs, neither ID, and null/blank/non-string IDs now fail with a clear error. An omitted or undefined unused identifier remains valid.

Add public limit and market order tests with real signing and mocked HTTP. They cover automatic V3 signing, V1/V2 overrides still routing positions to V3, position-based tick/fee/book lookups, balance adjustment, and the complete posting payload with the position in tokenId. Token order version selection remains unchanged.

Validation: 355 tests pass; Biome, ESM/CJS build with declarations, TypeScript --noEmit, and diff checks pass. The new validation regressions failed before the fix. HTTP is mocked; no live orders were submitted.

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Note

Medium Risk
Stricter runtime validation can break callers that previously passed ambiguous or malformed IDs; order creation paths are affected but behavior for valid inputs is preserved.

Overview
Order identifier validation is tightened in resolveOrderAssetID: callers must supply exactly one of tokenID or positionID as a non-empty string. Ambiguous or bad inputs (both set, neither set, null, blank/whitespace-only, or non-string values) now throw a clear error before metadata fetches, signing, or HTTP posts. An omitted/undefined unused field still works as before.

Tests add unit coverage for the new validation on both resolveOrderAssetID and resolveOrderRouting, plus integration-style client tests for public limit/market position orders (real signing, mocked HTTP): Exchange V3 signing regardless of version override, position-based tick/fee/book lookups, balance-adjusted amounts, full /order payload with the position in tokenId, early rejection without side effects, and unchanged token-order version routing.

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