Test regex alternations

When unit tests depend on filename/path classification via regex (e.g., routing maintainers, detecting test files), add explicit test cases that exercise every alternation token and mapping entry in the regex/table. Uncovered alternations can fail silently if someone introduces a typo or refactors part of the pattern.

Apply this by:

• For each regex like ...|...|..., create at least one classify([...]) test per branch (e.g., .test., .spec., __tests__, .test-utils.).
• For each DOMAIN_MAP entry that uses alternation groups (e.g., a|b|c), add a test that targets a path matching that exact alternation.

Example (illustrative unit tests):

it('treats .spec. as test-only', () => {
  const result = classify(['packages/core/src/tools/grep.spec.ts'], 'someone');
  assert.equal(result.reviewers.length, 0);
  assert.match(result.reason, /test-only/);
});

it('routes services compaction paths to the right domain expert', () => {
  const result = classify(['packages/core/src/services/compactionService.ts'], 'someone');
  assert.ok(result.reviewers.includes('LaZzyMan'));
});