test(perps): migrate controller unit tests to core

[abretonc7s]

Explanation

This PR migrates the mobile perps controller unit tests into @metamask/perps-controller so Core owns the controller test suite. It ports the mobile coverage into Core-native tests/src files, splits the largest controller/provider/subscription suites into focused shards, adds shared test helpers, and switches package coverage collection from the placeholder test to real src/**/*.ts coverage.

The package now enforces at least 80% statement/line coverage for the perps controller package. This is test-only and does not change the published runtime API.

Validation performed:

• yarn workspace @metamask/perps-controller run test --runInBand
  • 82.89% statements
  • 82.89% lines
  • 78.61% functions
  • 70.06% branches
• yarn eslint 'packages/perps-controller/{src,tests}/**/*.ts'
• yarn lint:misc --check
• yarn workspace @metamask/perps-controller run changelog:validate

Known limitation: yarn tsc --build packages/perps-controller/tsconfig.build.json --verbose is blocked by existing workspace dependency type errors outside this PR, first in accounts-controller / snap-account-service keyring exports, so the perps package is skipped by project references.

References

No related Core GitHub issue found for perps controller tests core.

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate (not applicable; test-only migration)
• I've communicated my changes to consumers by updating changelogs for packages I've changed (not applicable; test-only, no consumer-facing change)
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Low risk since changes are test-only, but they significantly expand and restructure the @metamask/perps-controller Jest suite and relax coverage thresholds, which could affect CI behavior and coverage enforcement.

Overview
Migrates the Perps controller unit test suite into @metamask/perps-controller, adding shared mock helpers (tests/helpers/*) and a large set of new controller tests split across focused shards (PerpsController.*.test.ts).

Updates the package Jest config to collect coverage from real src/**/*.ts (excluding barrel index.ts files) and adjusts enforced global coverage thresholds from 100% to 70% branches / 78% functions / 80% lines+statements.

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