fix(sdk): validate numeric and bigint round IDs consistently

[s6pa1rta3n-lab]

Summary

Fixes #256

Enforces a consistent positive safe-integer contract across string, number, and bigint inputs in normalizeRoundId:

• Rejects zero and negative numbers and bigints (<= 0n or <= 0).
• Rejects unsafe, fractional, and non-finite JavaScript numbers (NaN, Infinity, 1.5, Number.MAX_SAFE_INTEGER + 1).
• Validates string inputs using positive decimal digit matching.
• Preserves existing valid string, number, and bigint inputs.
• Adds comprehensive boundary unit tests.

Payout Stipulations Checklist

• Zero and negative number or bigint inputs are rejected.
• Unsafe, fractional, and non-finite numbers are rejected.
• Existing valid inputs remain unchanged.
• SDK tests and typecheck pass.

Payout Routing

• EVM (Base/Arbitrum/Polygon/ETH): 0xF46C9F6d70C50BF81ef3588AB523a90a594a2F89
• Stellar: GCL6OXAMLD75BMTINA6EMRUDWK5THQUSHMYNLSNBCJAPZJHNYJTUNIBC