refactor: Upgrade to TypeScript 5.9.2

[ivov]

https://devblogs.microsoft.com/typescript/announcing-typescript-5-9/

[ivov]

ArrayBuffer is no longer a supertype of TypedArray types like Buffer and Uint8Array.

[cubic-dev-ai]

cubic analysis

1 issue found across 4 files • Review in cubic

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[cubic-dev-ai]

Unnecessary creation of Uint8Array causes an extra memory copy; Buffer.from(ArrayBuffer) already works and avoids the overhead. (Based on your team's feedback about focusing on performance-impacting issues.)

Prompt for AI agents

Address the following comment on packages/cli/src/task-runners/task-broker/task-broker-ws-server.ts at line 104:

<comment>Unnecessary creation of `Uint8Array` causes an extra memory copy; `Buffer.from(ArrayBuffer)` already works and avoids the overhead. (Based on your team&#39;s feedback about focusing on performance-impacting issues.)</comment>

<file context>
@@ -99,7 +99,9 @@ export class TaskBrokerWsServer {
 
 		const onMessage = async (data: WebSocket.RawData) =&gt; {
 			try {
-				const buffer = Array.isArray(data) ? Buffer.concat(data) : Buffer.from(data);
+				const buffer = Array.isArray(data)
+					? Buffer.concat(data)
+					: Buffer.from(data instanceof ArrayBuffer ? new Uint8Array(data) : data);
 
 				const message: RunnerMessage.ToBroker.All = JSON.parse(
</file context>

[tomi]

cubic has a point here. When we wrap data in an UInt8Array it causes an unnecessary memory copy (see this). I think it's because the Buffer.from overload fails to infer the correct usage. This works and doesn't do extra allocations (tho not the prettiest):

const buffer = Array.isArray(data)
	? Buffer.concat(data)
	: data instanceof ArrayBuffer
		? Buffer.from(data)
		: data;

It also seems that we have done the memory copy all this time without realizing (as Buffer.from copies when the input is another instanceof Buffer). We could fix this now or merge this first and I can fix it afterwards.