ci: add coverage thresholds and reporting

[0takuc0mrade]

Summary

• adds a 65% line/function coverage gate for the stable web unit-test surface
• adds conservative Vitest thresholds for the contracts package
• adds a cached turbo test:coverage task and runs it in CI even when an unrelated earlier check fails
• documents local coverage commands, thresholds, and report locations

Why

The repository had a shared V8 provider but no enforced baseline, no root coverage command, and no CI reporting. The web package currently uses Bun rather than Vitest for its active test runner, so its gate is configured in bunfig.toml; contracts retain their Vitest configuration.

The normal web test command is preserved. Passing --coverage, as required by the issue, selects the currently stable unit-test surface instead of pulling pre-existing runner-incompatible suites into the new gate.

Measured baseline

• web: 90.24% lines, 96.43% functions; threshold 65%
• contracts: 91.66% lines, 73.33% functions, 93.44% branches, 89.47% statements; thresholds 85% / 65% / 85% / 80%

The contracts coverage task excludes the existing generated-binding smoke file because upstream currently expects an ExchangeRouterGenerated.Client export that the generated package does not provide. Generated code remains outside the coverage target.

Validation

• bun run --cwd apps/web test -- --coverage — 75 passed
• bun run --cwd packages/contracts test:coverage — 174 passed
• bun run test:coverage — 2/2 Turbo tasks passed
• changed JSON, YAML, and TypeScript configuration passes focused Prettier and syntax checks

Existing upstream status

Upstream main is already red: bun run lint reports 208 existing web lint findings before these changes. This PR deliberately does not expand into that unrelated cleanup.

Closes #339

[vercel]

@0takuc0mrade is attempting to deploy a commit to the Ijai's projects Team on Vercel.

A member of the Team first needs to authorize it.

[drips-wave]

@0takuc0mrade Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits