fix(tests): handle all Close() and Decode() errors across integration tests

Replace all unhandled resp.Body.Close() calls throughout the test suite:

- Deferred calls: replace 'defer VAR.Body.Close()' with a closure that explicitly
  discards the error via 'defer func(Body io.ReadCloser) { _ = Body.Close() }(VAR.Body)'
- Immediate calls: replace 'VAR.Body.Close()' with '_ = VAR.Body.Close()'

Replace all unhandled json.NewDecoder(VAR.Body).Decode(&x) calls with error capture
and require.NoError assertion. Files using httptest.ResponseRecorder (collections_preview,
processing_issues) use 'err :=' declaration; suite-style tests (scanner_integration,
dashboard_integration) use s.T() instead of t.

cmd/server/tests/device_cap_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/base64"
 	"encoding/json"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -68,7 +69,9 @@ func TestUpdateUserMaxDevices(t *testing.T) {
 			client := &http.Client{}
 			resp, err := client.Do(req)
 			require.NoError(t, err)
-			defer resp.Body.Close()
+			defer func(Body io.ReadCloser) {
+				_ = Body.Close()
+			}(resp.Body)
 
 			assert.Equal(t, tt.expectedStatus, resp.StatusCode, "expected status code")
 
@@ -134,7 +137,9 @@ func TestUpdateUserMaxDevicesValidation(t *testing.T) {
 			client := &http.Client{}
 			resp, err := client.Do(req)
 			require.NoError(t, err)
-			defer resp.Body.Close()
+			defer func(Body io.ReadCloser) {
+				_ = Body.Close()
+			}(resp.Body)
 
 			assert.Equal(t, tt.expectedStatus, resp.StatusCode, "expected validation error")
 		})
@@ -166,7 +171,9 @@ func TestUpdateUserMaxDevicesAuth(t *testing.T) {
 		client := &http.Client{}
 		resp, err := client.Do(req)
 		require.NoError(t, err)
-		defer resp.Body.Close()
+		defer func(Body io.ReadCloser) {
+			_ = Body.Close()
+		}(resp.Body)
 
 		assert.Equal(t, http.StatusUnauthorized, resp.StatusCode)
 	})
@@ -190,7 +197,9 @@ func TestUpdateUserMaxDevicesAuth(t *testing.T) {
 		client := &http.Client{}
 		resp, err := client.Do(req)
 		require.NoError(t, err)
-		defer resp.Body.Close()
+		defer func(Body io.ReadCloser) {
+			_ = Body.Close()
+		}(resp.Body)
 
 		assert.Equal(t, http.StatusForbidden, resp.StatusCode)
 	})
@@ -221,7 +230,9 @@ func TestUpdateUserMaxDevicesNonExistentUser(t *testing.T) {
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	// Should return 500 or 404 depending on implementation
 	assert.True(t, resp.StatusCode == http.StatusInternalServerError || resp.StatusCode == http.StatusNotFound)
@@ -250,7 +261,9 @@ func TestUpdateUserMaxDevicesMissingUserID(t *testing.T) {
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	assert.Equal(t, http.StatusBadRequest, resp.StatusCode)
 }
@@ -271,12 +284,15 @@ func TestListUsersIncludesMaxDevices(t *testing.T) {
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	assert.Equal(t, http.StatusOK, resp.StatusCode)
 
 	var users []map[string]interface{}
-	json.NewDecoder(resp.Body).Decode(&users)
+	err = json.NewDecoder(resp.Body).Decode(&users)
+	require.NoError(t, err)
 
 	// Verify max_devices and device_count fields are present in response
 	if len(users) > 0 {
@@ -306,7 +322,7 @@ func createAdminUser(t *testing.T, ts *httptest.Server, token string) {
 
 	client := &http.Client{}
 	resp, _ := client.Do(req)
-	resp.Body.Close()
+	_ = resp.Body.Close()
 }
 
 // Helper function to create test user for max devices tests
@@ -327,7 +343,9 @@ func createTestUserForMaxDevices(t *testing.T, ts *httptest.Server, adminToken s
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	// Check if user creation succeeded or already exists (409 Conflict)
 	if resp.StatusCode == http.StatusConflict {
@@ -343,10 +361,13 @@ func createTestUserForMaxDevices(t *testing.T, ts *httptest.Server, adminToken s
 
 		loginResp, err := client.Do(loginReq)
 		require.NoError(t, err)
-		defer loginResp.Body.Close()
+		defer func(Body io.ReadCloser) {
+			_ = Body.Close()
+		}(loginResp.Body)
 
 		var loginResult map[string]interface{}
-		json.NewDecoder(loginResp.Body).Decode(&loginResult)
+		err = json.NewDecoder(loginResp.Body).Decode(&loginResult)
+		require.NoError(t, err)
 
 		// Extract user_id from JWT or response
 		// The access_token contains the user ID in the JWT claims
@@ -392,7 +413,8 @@ func createTestUserForMaxDevices(t *testing.T, ts *httptest.Server, adminToken s
 	}
 
 	var result map[string]interface{}
-	json.NewDecoder(resp.Body).Decode(&result)
+	err = json.NewDecoder(resp.Body).Decode(&result)
+	require.NoError(t, err)
 
 	// Check if user creation was successful
 	if result["user"] == nil {
@@ -422,10 +444,13 @@ func getAdminToken(t *testing.T, ts *httptest.Server, userID uuid.UUID) string {
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	var result map[string]interface{}
-	json.NewDecoder(resp.Body).Decode(&result)
+	err = json.NewDecoder(resp.Body).Decode(&result)
+	require.NoError(t, err)
 
 	// Safe type assertion with check
 	if accessToken, ok := result["access_token"].(string); ok {
@@ -450,10 +475,13 @@ func loginTestUserByCredentials(t *testing.T, ts *httptest.Server, email, passwo
 	client := &http.Client{}
 	resp, err := client.Do(req)
 	require.NoError(t, err)
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
 
 	var result map[string]interface{}
-	json.NewDecoder(resp.Body).Decode(&result)
+	err = json.NewDecoder(resp.Body).Decode(&result)
+	require.NoError(t, err)
 
 	// Safe type assertion with check
 	if accessToken, ok := result["access_token"].(string); ok {