Schema descriptions and examples added across API references

Broker API

Documentation coverage improves across several Broker schemas, with no change to request or response payloads:

• Adds descriptions to the shared non-trade activity schemas CommonNTAActivityV2 and CommonJournalActivityV2.
• Adds a description to DailyTradingLimit explaining the correspondent-level daily net buying limit and the amount currently consuming it.
• Clarifies the funding status event description to name the supported entities (bank relationships, bank wires, transfers, and funding wallets).
• Simplifies redundant single-item schema combinators on the ACATS and activity schemas; the documented fields and values are unchanged.

Affected Endpoints

• GET /v2beta1/events/activities
• GET /v2beta1/accounts/{account_id}/events/activities/{event_id}
• GET /v1/transfers/jit/limits
• GET /v2/events/funding/status
• POST /v1beta1/acats/{account_id}
• GET /v1beta1/acats
• GET /v1beta1/acats/{account_id}

Market Data API

The fixed-income latest price and quote response schemas now carry descriptions and worked response examples keyed by ISIN. Redundant single-item combinators on the sort query parameter of the historical stock and corporate action endpoints were flattened, with no change to accepted values.

Affected Endpoints

• GET /v1beta1/fixed_income/latest/prices
• GET /v1beta1/fixed_income/latest/quotes

Auth API

The Authx API description now includes a top-level service description in the reference. No request or response shapes changed.