`codegraph affected` kept six regexes of its own — `.test.`, `.spec.`,
`/tests/`… — so a Go `foo_test.go`, a Python `test_foo.py` or a JVM
`FooTest.kt` beside the changed file was never reported, and "no tests
affected" read as "no coverage". Use isTestPath from search/query-utils,
the same predicate search and the MCP tools already rank by.
Cherry-picked from danusha2345's upstream PR #1688
(commit 995b6f1f262564cafa6eb0b026b84fa4122f2cb0).
Preserve main's CLI imports and Unreleased entries, and credit the
contributor in the changelog. The default affected depth remains 5.
Fixes#1507.
Supersedes #1688.
Verified on Linux with Node 22.19.0: npm run build; the Go fixture
changes from no affected tests to math_test.go; matching and nonmatching
custom filters still override. Vitest: 3 files, 36 tests passed, including
the upstream Go/Python/Kotlin suite and affected path/dependency coverage.
Co-authored-by: danusha2345 <ewidusoc498@gmail.com>
