Apps (web-next, web-tanstack, cms) do not configure @vitest/coverage-v8 so their source files never appear in the merged lcov; gate them out of the cover-the-diff check. core-shared/src/instrumentation/sentry/** is explicitly excluded from per-package vitest coverage (see core-shared/vitest.config.ts) — exclude from the diff gate to mirror that decision. Adds tests for both new exclusion patterns. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>