chore: adopt @unthrown/oxlint recommended rules

[btravers]

Summary

Registers the @unthrown/oxlint plugin with the four recommended rules (no-ambiguous-error-type, no-catch-all-pattern, no-unhandled-result, prefer-async-result; the opt-ins no-throw/prefer-ensure stay off — the worker's sanctioned ValidationError throws would fight no-throw). @unthrown/oxlint joins the first-party minimumReleaseAgeExclude list (published inside the 7-day supply-chain gate; same treatment as unthrown and @unthrown/vitest).

The rules found 29 violations; 24 real fixes, 2 targeted disables:

• Genuine public-type imprecision caught by no-ambiguous-error-type: the exported ClientInferSignal/Query/Update aliases claimed AsyncResult<..., Error> while the proxies actually produce {Signal,Query,Update}ValidationError | WorkflowExecutionNotFoundError. The aliases now carry the concrete unions, and the mapped conditionals in client.ts that papered over the lie collapsed to identity — TypedWorkflowHandle now references the aliases directly.
• prefer-async-result: 16 internal work-thunk Promise<Result> annotations dropped (with explicit type arguments pinned at makeAsyncResult call sites where TS can't collapse per-return Result unions); 3 named async helpers converted to non-async AsyncResult-returning functions (behavior proven unchanged — callers' assertNoDefect already re-threw into the enclosing throw→defect net).
• 2 disables, both on the sanctioned Promise→AsyncResult conversion seam (_internal_makeAsyncResult and its client re-export), each with the reason inline.
• Spec fixtures' AsyncResult<unknown, unknown> replaced with the concrete ProxyError union the code actually produces.

Cherry-picked from the post-#354 branch onto main. Mirror adoption in amqp-contract: btravstack/amqp-contract#613.

Verification

pnpm lint clean; pnpm turbo run typecheck test 16/16 tasks; per-package: client 140, worker 182, contract 120, testing 19 tests passing.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adopts the @unthrown/oxlint plugin and enables its recommended rules to enforce more precise AsyncResult/Result usage and error unions across the Temporal contract client/worker/testing packages.

Changes:

• Register @unthrown/oxlint in .oxlintrc.json and add the dependency via the workspace catalog (including supply-chain gate exclusion).
• Tighten the client public type surface by replacing AsyncResult<..., Error> with concrete validation/not-found error unions, and simplify TypedWorkflowHandle mapped types accordingly.
• Refactor several internal helpers from Promise<Result<...>> to AsyncResult<...> (and remove now-redundant Promise<Result> annotations), plus align test fixtures with the real proxy error union.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pnpm-workspace.yaml	Adds @unthrown/oxlint to the catalog and supply-chain exclusion list.
pnpm-lock.yaml	Locks @unthrown/oxlint (and its transitive deps) into the workspace.
package.json	Adds @unthrown/oxlint as a root devDependency via the catalog.
.oxlintrc.json	Registers the unthrown plugin and enables the recommended rules.
packages/contract/src/result-async.ts	Documents and disables prefer-async-result at the intentional Promise→AsyncResult seam.
packages/client/src/internal.ts	Documents and disables prefer-async-result at the client’s Promise→AsyncResult seam wrapper.
packages/client/src/types.ts	Replaces ambiguous Error error types with concrete validation/not-found unions for signals/queries/updates.
packages/client/src/client.ts	Simplifies TypedWorkflowHandle query/signal/update types now that aliases carry correct unions; converts resolver helper to AsyncResult.
packages/client/src/schedule.ts	Removes explicit Promise<Result<...>> annotations and pins makeAsyncResult generics at call sites.
packages/worker/src/child-workflow.ts	Converts validation helpers to AsyncResult and pins makeAsyncResult generics where inference can’t collapse unions.
packages/worker/src/cancellation.ts	Removes explicit Promise<Result<...>> annotations and pins makeAsyncResult generics.
packages/worker/src/activities-proxy.spec.ts	Replaces AsyncResult<unknown, unknown> with a concrete proxy error union in fixtures.
packages/testing/src/activity.ts	Removes explicit Promise<Result<...>> annotation in the internal run wrapper while preserving behavior.

Files not reviewed (1)

• pnpm-lock.yaml: Generated file

[Copilot]

Pull request overview

Copilot reviewed 30 out of 31 changed files in this pull request and generated no new comments.

Files not reviewed (1)

• pnpm-lock.yaml: Generated file

Comments suppressed due to low confidence (1)

.oxlintrc.json:20

• PR description says the opt-in rules unthrown/no-throw and unthrown/prefer-ensure should stay off, but .oxlintrc.json enables both as error (and even adds an override to partially relax no-throw). This makes the lint config disagree with the stated intent and is why so many oxlint-disable-next-line unthrown/no-throw directives were introduced.

  "rules": {
    "unthrown/no-ambiguous-error-type": "error",
    "unthrown/no-catch-all-pattern": "error",
    "unthrown/no-throw": "error",
    "unthrown/no-unhandled-result": "error",
    "unthrown/prefer-async-result": "error",
    "unthrown/prefer-ensure": "error"
  },