style: adopt golangci-lint v2 and resolve all findings

Add .golangci.yml (v2): the standard linters plus bodyclose, errorlint, noctx, misspell, rowserrcheck, sqlclosecheck, unconvert, usestdlibvars, with gofumpt + goimports formatters. Enable the std-error-handling exclusion preset for idiomatic Close/Remove/Setenv ignores; scope-exclude SA1019 (parser.ParseDir in tools/openapigen) and ST1005 (intentional capitalized user-facing error copy that tests assert verbatim). No inline nolint directives were introduced.

Resolve all 217 findings behavior-preserving: gofumpt/goimports formatting, explicit blank assignment on intentionally ignored errors, errors.Is/errors.As and %w wrapping, context-aware stdlib calls (CommandContext/QueryContext/NewRequestWithContext/Dialer), staticcheck simplifications, removed redundant conversions, http.StatusOK and http.MethodGet, inlined the go:fix intPtr helper, and deferred sql rows Close. Add a golangci CI job mirroring the existing Go jobs.

internal/xray/process.go

@@ -2,6 +2,7 @@ package xray
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -74,7 +75,7 @@ func GetAccessLogPath() (string, error) {
 	}
 
 	jsonConfig := map[string]any{}
-	err = json.Unmarshal([]byte(config), &jsonConfig)
+	err = json.Unmarshal(config, &jsonConfig)
 	if err != nil {
 		logger.Warningf("Failed to parse JSON configuration: %s", err)
 		return "", err
@@ -92,7 +93,7 @@ func GetAccessLogPath() (string, error) {
 
 // stopProcess calls Stop on the given Process instance.
 func stopProcess(p *Process) {
-	p.Stop()
+	_ = p.Stop()
 }
 
 // Process wraps an Xray process instance and provides management methods.
@@ -475,7 +476,7 @@ func (p *process) refreshAPIPort() {
 
 // refreshVersion updates the version string by running the Xray binary with -version.
 func (p *process) refreshVersion() {
-	cmd := exec.Command(GetBinaryPath(), "-version")
+	cmd := exec.CommandContext(context.Background(), GetBinaryPath(), "-version")
 	data, err := cmd.Output()
 	if err != nil {
 		p.version = "Unknown"
@@ -521,7 +522,7 @@ func (p *process) Start() (err error) {
 		return common.NewErrorf("Failed to write configuration file: %v", err)
 	}
 
-	cmd := exec.Command(GetBinaryPath(), "-c", configPath)
+	cmd := exec.CommandContext(context.Background(), GetBinaryPath(), "-c", configPath)
 	cmd.Stdout = p.logWriter
 	cmd.Stderr = p.logWriter
 

internal/xray/process_test.go

@@ -12,8 +12,9 @@ import (
 	"testing"
 	"time"
 
-	xuilogger "github.com/mhsanaei/3x-ui/v3/internal/logger"
 	"github.com/op/go-logging"
+
+	xuilogger "github.com/mhsanaei/3x-ui/v3/internal/logger"
 )
 
 func TestWriteFileAtomicModeAndRenameFailure(t *testing.T) {
@@ -203,7 +204,7 @@ func markProcessHelperReady(t *testing.T) {
 	if readyPath == "" {
 		t.Fatal("XRAY_PROCESS_READY is not set")
 	}
-	if err := os.WriteFile(readyPath, []byte("ready"), 0644); err != nil {
+	if err := os.WriteFile(readyPath, []byte("ready"), 0o644); err != nil {
 		t.Fatalf("write helper ready file: %v", err)
 	}
 }

internal/xray/process_windows.go

@@ -7,8 +7,9 @@ import (
 	"sync"
 	"unsafe"
 
-	"github.com/mhsanaei/3x-ui/v3/internal/logger"
 	"golang.org/x/sys/windows"
+
+	"github.com/mhsanaei/3x-ui/v3/internal/logger"
 )
 
 var (
@@ -36,7 +37,7 @@ func ensureKillOnExitJob() (windows.Handle, error) {
 			uint32(unsafe.Sizeof(info)),
 		)
 		if err != nil {
-			windows.CloseHandle(h)
+			_ = windows.CloseHandle(h)
 			killOnExitJobErr = err
 			return
 		}
@@ -59,7 +60,7 @@ func attachChildLifetime(cmd *exec.Cmd) {
 		logger.Warning("xray: OpenProcess for job attach failed:", err)
 		return
 	}
-	defer windows.CloseHandle(h)
+	defer func() { _ = windows.CloseHandle(h) }()
 	if err := windows.AssignProcessToJobObject(job, h); err != nil {
 		logger.Warning("xray: AssignProcessToJobObject failed:", err)
 	}