fix(cli): affected shares the tool's one notion of a test file (#1507) (#1803)

`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>

CHANGELOG.md

@@ -227,6 +227,8 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 #### Symbols, tests and the viewer
 
+- `codegraph affected` now finds Go, Python and JVM test files that previously went unreported, while preserving custom `--filter` behavior (thanks @danusha2345; #1507, #1688).
+
 - Calls inside declaration initializers in Kotlin, Java, TypeScript, JavaScript, Scala, Rust and Python now appear under the declaration that owns them, making callers and impact results more accurate after re-indexing with `codegraph index -f` (thanks @danusha2345; #1510, #1511).
 - Java fields initialized with anonymous classes now expose their methods and calls in the graph.
 - Kotlin property accessors, initialization blocks and destructuring declarations now retain their calls with the correct owner.