- Strip VCS_TYPE and VCS_URL in cleanEnv() to prevent env leakage in
  subprocess tests when VCS_TYPE=github is set in the runner environment
  (fixes #135)

- Add TestGithubAPIURL table-driven tests covering:
  - Empty string defaults to https://api.github.com
  - https://github.com maps to https://api.github.com
  - Trailing slash variant maps correctly
  - GHES host (ghe.example.com) gets /api/v3 suffix
  - GHES concur domain does not map to api.github.com
  (fixes #134)

- Add TestIntegration_GitHub_PostAndVerifyReview: exercises the GitHub
  adapter end-to-end via VCS_TYPE=github. Skips gracefully when
  INTEGRATION_GITHUB_TOKEN, INTEGRATION_GITHUB_REPO, and
  INTEGRATION_GITHUB_PR are not set. Verifies GetAuthenticatedUser,
  GetPullRequest, PostReview, and ListReviews succeed; notes that
  DeleteReview on submitted GitHub reviews is expected to fail (422).
  (fixes #133)

@@ -162,0 +195,4 @@
+
+	ctx := context.Background()
+
+	// Verify the GitHub adapter is selected via VCS routing.

@@ -162,0 +234,4 @@
+			found = true
+			break
+		}
+	}

@@ -162,0 +194,4 @@
+	owner, repoName := parts[0], parts[1]
+
+	ctx := context.Background()
+	ghClient := github.NewClient(githubToken, "https://api.github.com")

@@ -162,0 +227,4 @@
+	found := false
+	for _, r := range reviews {
+		if r.ID == posted.ID && strings.Contains(r.Body, sentinel) {
+			found = true

@@ -159,3 +160,85 @@ func TestIntegration_PostAndCleanup(t *testing.T) {
 		t.Logf("Warning: could not delete test review %d: %v", posted.ID, err)
 	}
 }
+

@@ -162,0 +197,4 @@
+	ghClient := github.NewClient(githubToken, "https://api.github.com")
+
+	// Verify adapter selection: GetAuthenticatedUser must succeed.
+	user, err := ghClient.GetAuthenticatedUser(ctx)

@@ -162,0 +204,4 @@
+	t.Logf("Authenticated as: %s", user)
+
+	// Verify PR is accessible via GitHub adapter.
+	pr, err := ghClient.GetPullRequest(ctx, owner, repoName, prNumber)