SDK regeneration

[chiragjn]

Note

Medium Risk
OMIT vs None changes how create_turn and SSE subscribe requests are encoded, which can alter turn chaining and resume behavior for callers that relied on implicit None. Removing external-identity from the enum is a breaking type/API surface change for filters using that subject type.

Overview
Regenerates the TrueFoundry Gateway Python SDK from the updated API definition (Fern CLI 5.80.2, generator 5.22.1), including lockfile bumps for optional httpx-aiohttp (0.1.12).

Optional request parameters on agent turn/session helpers now default to an OMIT sentinel instead of None, so omitted kwargs are not serialized as explicit JSON nulls and server defaults (e.g. previous_turn_id → auto) still apply. PreparedTurn keeps a separate _input_param when forwarding to create_turn. stream() / after_sequence_number docs now note that omitting the arg resumes via Last-Event-Id rather than a query param.

API-aligned type changes: PreviousTurnIdInput adds the "none" literal; CreatedBySubjectType drops external-identity / EXTERNAL_IDENTITY from the enum and visit() API (unknown values still map via forward-compat _UNKNOWN).

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