fix: add nolint:errcheck comments for intentionally unchecked errors

Add //nolint:errcheck comments to intentionally unchecked error returns:

- defer X.Close() calls: errors from closing read-only resources, rows
  after iteration, files, response bodies, and gzip readers are not
  actionable and don't affect correctness

- defer tx.Rollback(): standard Go pattern where rollback after
  successful commit returns an error, which is expected behavior

- defer stmt.Close(): statements are closed with their transactions

- Cleanup operations: DeleteRevision on failure and os.RemoveAll for
  temp directories are best-effort cleanup

- HTTP response encoding: if JSON encoding fails at response time,
  there's nothing useful we can do

- Test/benchmark code: unchecked errors in test setup/cleanup where
  failures will surface through test assertions

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/mcp/transport_http_test.go

@@ -59,7 +59,7 @@ func TestHTTPTransportInitialize(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Errorf("Expected 200, got %d", resp.StatusCode)
@@ -103,7 +103,7 @@ func TestHTTPTransportSessionRequired(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusBadRequest {
 		t.Errorf("Expected 400 without session, got %d", resp.StatusCode)
@@ -129,7 +129,7 @@ func TestHTTPTransportInvalidSession(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusNotFound {
 		t.Errorf("Expected 404 for invalid session, got %d", resp.StatusCode)
@@ -158,7 +158,7 @@ func TestHTTPTransportValidSession(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Errorf("Expected 200 with valid session, got %d", resp.StatusCode)
@@ -185,7 +185,7 @@ func TestHTTPTransportNotificationAccepted(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusAccepted {
 		t.Errorf("Expected 202 for notification, got %d", resp.StatusCode)
@@ -210,7 +210,7 @@ func TestHTTPTransportDeleteSession(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusNoContent {
 		t.Errorf("Expected 204 for delete, got %d", resp.StatusCode)
@@ -232,7 +232,7 @@ func TestHTTPTransportDeleteNonexistentSession(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusNotFound {
 		t.Errorf("Expected 404 for nonexistent session, got %d", resp.StatusCode)
@@ -315,7 +315,7 @@ func TestHTTPTransportOriginValidation(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Request failed: %v", err)
 			}
-			defer resp.Body.Close()
+			defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 			if tt.expectAllowed && resp.StatusCode == http.StatusForbidden {
 				t.Error("Expected request to be allowed but was forbidden")
@@ -340,7 +340,7 @@ func TestHTTPTransportSSERequiresAcceptHeader(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusNotAcceptable {
 		t.Errorf("Expected 406 without Accept header, got %d", resp.StatusCode)
@@ -361,7 +361,7 @@ func TestHTTPTransportSSEStream(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Fatalf("Expected 200, got %d", resp.StatusCode)
@@ -425,7 +425,7 @@ func TestHTTPTransportSSEKeepalive(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Fatalf("Expected 200, got %d", resp.StatusCode)
@@ -483,7 +483,7 @@ func TestHTTPTransportParseError(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Errorf("Expected 200 (with JSON-RPC error), got %d", resp.StatusCode)
@@ -511,7 +511,7 @@ func TestHTTPTransportMethodNotAllowed(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusMethodNotAllowed {
 		t.Errorf("Expected 405, got %d", resp.StatusCode)
@@ -530,7 +530,7 @@ func TestHTTPTransportOptionsRequest(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusNoContent {
 		t.Errorf("Expected 204, got %d", resp.StatusCode)
@@ -641,7 +641,7 @@ func TestHTTPTransportRequestBodyTooLarge(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusRequestEntityTooLarge {
 		t.Errorf("Expected 413 for oversized request, got %d", resp.StatusCode)
@@ -670,7 +670,7 @@ func TestHTTPTransportSessionLimitReached(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Request %d failed: %v", i, err)
 		}
-		resp.Body.Close()
+		resp.Body.Close() //nolint:errcheck // test cleanup
 
 		if resp.StatusCode != http.StatusOK {
 			t.Errorf("Request %d: expected 200, got %d", i, resp.StatusCode)
@@ -685,7 +685,7 @@ func TestHTTPTransportSessionLimitReached(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusServiceUnavailable {
 		t.Errorf("Expected 503 when session limit reached, got %d", resp.StatusCode)
@@ -713,7 +713,7 @@ func TestHTTPTransportRequestBodyWithinLimit(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Request failed: %v", err)
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck // test cleanup
 
 	if resp.StatusCode != http.StatusOK {
 		t.Errorf("Expected 200 for valid request within limit, got %d", resp.StatusCode)