[rami-hatoum]

What this changes

The suites leaked. On a machine that runs them, the temporary directory held 18 GB of folders the tests had made and never removed, thousands under each package's prefix, and the server suite left one ledger folder per run and, under load, a background runtime still running. Every helper removes what it makes on onTestFinished or in a finally, which a worker that dies, a hook that times out or a child that is killed never reaches, and nothing ever looked.

Now each test run owns a temporary folder of its own.

• A shared global setup, in vitest.shared.ts so every package has it, makes one folder under the machine's temporary directory, named for the run, and sets TMPDIR to it before any worker starts, so os.tmpdir() in every worker and in every process a test spawns answers that folder. The helpers needed no change for this.
• Its teardown always removes the folder whole, so a run can no longer leave anything behind, and before it does it looks: an entry left there is a test that did not clean up, and the run fails naming each one, so a leak is a red gate rather than a surprise on someone's disk. Two runs on one machine have two folders and never name each other's files.
• Under the server, the teardown also reads each left home's runtime.log for a runtime started in the background with no ending, ends it only while ps shows the instance the log named, SIGTERM then SIGKILL, and names it in the failure. The per-test hook that did this reads the log through the same function.

The gate then showed three leaks, each fixed at its root:

• The identity package's key test that reads an env file never removed the folder it wrote the file in.
• The server's computation test over MCP started a server twice and stopped only the second, which left one ledger folder per run.
• A model process of a prediction function wrote the model library's telemetry files into its temporary folder, which the fix that turns that telemetry off removes; this change builds on it.

turbo.json lists the setup's files under globalDependencies, so a change to them invalidates every package's cached test results, including those of packages that do not depend on operations.

Tests

• The folder is made where the run is set up, named for the run, is the temporary folder of the run and of a process it starts, and is gone after the teardown.
• A teardown that finds entries fails naming them in order and removes the folder all the same; two runs set up at once name only their own.
• A process still running in a home a test left is ended as the teardown looks, before the folder is removed, and named with what it ran in; the server's reader finds a started runtime with no ending in a home's log and nothing in a home whose runtime ended.
• The four server shards and their merge, three concurrent runs of one suite and a run of three projects in one process all leave no folder behind.

Checklist

• The PR title is a conventional commit with a workspace scope, such as feat(reasoning): .... It becomes the squash commit and the changelog entry.
• pnpm check passes locally, with every file at 100% coverage.
• I've signed the Contributor License Agreement (the CLA bot asks on your first PR).