Raise order() priority grouping cap from 80000 to 1e8

[joeblau]

Problem

src/api/exchange/_methods/order.ts:86 caps the priority grouping { p } value at 80000. The API now allows up to 1e8 (100%), so the SDK actively rejects valid orders.

Upstream reference: nktkas#169 (v0.33.x).

Fix

• Raise the cap in the order schema to 1e8 (or 100_000_000).
• Check the same constant isn't duplicated elsewhere (search for 80000).
• Add/adjust a test covering the new boundary.