Cross-language SDK parity: renames and removals

The Node, Python, and Rust SDKs are aligned to a consistent public surface. The main client handle, telemetry config, buffered HTTP types, and several stream types are renamed, and a set of redundant exports is removed.

What changed

The three SDKs are aligned so the same concept has the same name everywhere. This slice renames several public types and removes redundant or dead exports. Behavior is unchanged; the wire format is unchanged.

Renames

Concept	Before	After
Main client handle	Node ISdk, Rust III	IIIClient (all three)
Telemetry config	Rust WorkerTelemetryMeta	TelemetryOptions
Buffered HTTP request and response	ApiRequest, ApiResponse	HttpRequest, HttpResponse
Stream change event (Rust)	StreamCallRequest	StreamChangeEvent
Stream join and leave event (Rust)	StreamJoinLeaveCallRequest	StreamJoinLeaveEvent
Stream change event detail	Rust StreamEventDetail, Node inline object	StreamChangeEventDetail (all three)
Stream set result	Rust SetResult	StreamSetResult (all three)
Stream update result	Rust UpdateResult	StreamUpdateResult (all three)
Stream delete result	Rust and Node DeleteResult	StreamDeleteResult (all three)

The streaming request and response types keep the StreamRequest and StreamResponse names. The buffered types reclaim the HttpRequest and HttpResponse names from them. EngineFunctions and EngineTriggers are now present in the Python and Rust SDKs as well, not only Node. MergePath (the path argument for merge and append update operations) is now a named export in all three SDKs.

Removals

Removed	SDK	Replacement
UpdateBuilder	Rust	use UpdateSet and UpdateMerge directly
Value re-export	Rust	depend on serde_json directly
IIIForbiddenError, IIITimeoutError	Python	check the error code on the invocation error, matching Node and Rust
TriggerActionType alias	Node	use the TriggerAction value
FieldPath (separate path helper)	Rust	use UpdateSet and UpdateMerge; the merge and append path argument is the retained MergePath
Logger re-export	Node	import from @iii-dev/helpers/observability
OpenTelemetry suite re-export	Python	import from iii_helpers.observability

Migration

Update any imports that reference the old names. The renames are mechanical. For the removed Python error subclasses, branch on the error code instead of catching the dedicated subclass:

# Before
try:
    ...
except IIIForbiddenError:
    ...
# After
except InvocationError as err:
    if err.code == "forbidden":
        ...

Why

A flat, divergent surface made the SDKs harder to learn and harder to keep in sync. Aligning the names so the same import means the same thing in every language, and dropping exports that duplicated functionality available elsewhere, makes the surface smaller and predictable.