refactor: apply go fix modernizations for Go 1.26

Run `go fix ./...` to apply automated code modernizations:
- interface{} → any
- Remove unnecessary loop variable copies (Go 1.22+ semantics)
- String concatenation → strings.Builder
- Manual loops → slices.Contains, maps.Copy
- strings.Split → strings.SplitSeq where applicable
- Remove redundant struct tags

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

https://claude.ai/code/session_01WLKDmB7kemgPsjsj9KFEXa

Author: claude

internal/cmd/cmd.go

@@ -100,7 +100,7 @@ var initCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		var yamlConfig interface{}
+		var yamlConfig any
 		if useV1 {
 			yamlConfig = config.V1GenerateSettings{Version: "1"}
 		} else {

internal/cmd/createdb.go

@@ -47,7 +47,6 @@ func CreateDB(ctx context.Context, dir, filename, querySetName string, o *Option
 	var queryset *config.SQL
 	var count int
 	for _, sql := range conf.SQL {
-		sql := sql
 		if querySetName != "" && sql.Name != querySetName {
 			continue
 		}

internal/codegen/golang/field.go

@@ -97,23 +97,23 @@ func toPascalCase(s string) string {
 }
 
 func toCamelInitCase(name string, initUpper bool) string {
-	out := ""
+	var out strings.Builder
 	for i, p := range strings.Split(name, "_") {
 		if !initUpper && i == 0 {
-			out += p
+			out.WriteString(p)
 			continue
 		}
 		if p == "id" {
-			out += "ID"
+			out.WriteString("ID")
 		} else {
-			out += strings.Title(p)
+			out.WriteString(strings.Title(p))
 		}
 	}
-	return out
+	return out.String()
 }
 
 func toJsonCamelCase(name string, idUppercase bool) string {
-	out := ""
+	var out strings.Builder
 	idStr := "Id"
 
 	if idUppercase {
@@ -122,16 +122,16 @@ func toJsonCamelCase(name string, idUppercase bool) string {
 
 	for i, p := range strings.Split(name, "_") {
 		if i == 0 {
-			out += p
+			out.WriteString(p)
 			continue
 		}
 		if p == "id" {
-			out += idStr
+			out.WriteString(idStr)
 		} else {
-			out += strings.Title(p)
+			out.WriteString(strings.Title(p))
 		}
 	}
-	return out
+	return out.String()
 }
 
 func toLowerCase(str string) string {

internal/codegen/golang/gen.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"go/format"
+	"slices"
 	"strings"
 	"text/template"
 
@@ -344,10 +345,8 @@ func usesCopyFrom(queries []Query) bool {
 
 func usesBatch(queries []Query) bool {
 	for _, q := range queries {
-		for _, cmd := range []string{metadata.CmdBatchExec, metadata.CmdBatchMany, metadata.CmdBatchOne} {
-			if q.Cmd == cmd {
-				return true
-			}
+		if slices.Contains([]string{metadata.CmdBatchExec, metadata.CmdBatchMany, metadata.CmdBatchOne}, q.Cmd) {
+			return true
 		}
 	}
 	return false

internal/codegen/golang/go_type.go

@@ -1,6 +1,7 @@
 package golang
 
 import (
+	"maps"
 	"strings"
 
 	"github.com/sqlc-dev/sqlc/internal/codegen/golang/opts"
@@ -15,9 +16,7 @@ func addExtraGoStructTags(tags map[string]string, req *plugin.GenerateRequest, o
 			continue
 		}
 		if override.MatchesColumn(col) {
-			for k, v := range oride.GoType.StructTags {
-				tags[k] = v
-			}
+			maps.Copy(tags, oride.GoType.StructTags)
 			continue
 		}
 		if !override.Matches(col.Table, req.Catalog.DefaultSchema) {
@@ -33,9 +32,7 @@ func addExtraGoStructTags(tags map[string]string, req *plugin.GenerateRequest, o
 			continue
 		}
 		// Add the extra tags.
-		for k, v := range oride.GoType.StructTags {
-			tags[k] = v
-		}
+		maps.Copy(tags, oride.GoType.StructTags)
 	}
 }
 

internal/codegen/golang/opts/go_type.go

@@ -51,7 +51,7 @@ func (o *GoType) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-func (o *GoType) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (o *GoType) UnmarshalYAML(unmarshal func(any) error) error {
 	var spec string
 	if err := unmarshal(&spec); err == nil {
 		*o = GoType{Spec: spec}

internal/codegen/golang/result.go

@@ -168,17 +168,17 @@ func paramName(p *plugin.Parameter) string {
 }
 
 func argName(name string) string {
-	out := ""
+	var out strings.Builder
 	for i, p := range strings.Split(name, "_") {
 		if i == 0 {
-			out += strings.ToLower(p)
+			out.WriteString(strings.ToLower(p))
 		} else if p == "id" {
-			out += "ID"
+			out.WriteString("ID")
 		} else {
-			out += strings.Title(p)
+			out.WriteString(strings.Title(p))
 		}
 	}
-	return out
+	return out.String()
 }
 
 func buildQueries(req *plugin.GenerateRequest, options *opts.Options, structs []Struct) ([]Query, error) {

internal/codegen/golang/struct.go

@@ -31,7 +31,7 @@ func StructName(name string, options *opts.Options) string {
 		return rune('_')
 	}, name)
 
-	for _, p := range strings.Split(name, "_") {
+	for p := range strings.SplitSeq(name, "_") {
 		if _, found := options.InitialismsMap[p]; found {
 			out += strings.ToUpper(p)
 		} else {

internal/compiler/output_columns.go

@@ -517,7 +517,6 @@ func (c *Compiler) sourceTables(qc *QueryCatalog, node ast.Node) ([]*Table, erro
 
 	var tables []*Table
 	for _, item := range list.Items {
-		item := item
 		switch n := item.(type) {
 
 		case *ast.RangeFunction:

internal/config/config.go

@@ -36,7 +36,7 @@ func (p *Paths) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-func (p *Paths) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (p *Paths) UnmarshalYAML(unmarshal func(any) error) error {
 	out := []string{}
 	if sliceErr := unmarshal(&out); sliceErr != nil {
 		var ele string
@@ -61,7 +61,7 @@ type Config struct {
 	Cloud     Cloud                `json:"cloud" yaml:"cloud"`
 	Servers   []Server             `json:"servers" yaml:"servers"`
 	SQL       []SQL                `json:"sql" yaml:"sql"`
-	Overrides Overrides            `json:"overrides,omitempty" yaml:"overrides"`
+	Overrides Overrides            `json:"overrides" yaml:"overrides"`
 	Plugins   []Plugin             `json:"plugins" yaml:"plugins"`
 	Rules     []Rule               `json:"rules" yaml:"rules"`
 	Options   map[string]yaml.Node `json:"options" yaml:"options"`
@@ -125,8 +125,8 @@ type SQL struct {
 // AnalyzerDatabase represents the database analyzer setting.
 // It can be a boolean (true/false) or the string "only" for database-only mode.
 type AnalyzerDatabase struct {
-	value   *bool  // nil means not set, true/false for boolean values
-	isOnly  bool   // true when set to "only"
+	value  *bool // nil means not set, true/false for boolean values
+	isOnly bool  // true when set to "only"
 }
 
 // IsEnabled returns true if the database analyzer should be used.
@@ -166,7 +166,7 @@ func (a *AnalyzerDatabase) UnmarshalJSON(data []byte) error {
 	return errors.New("analyzer.database must be true, false, or \"only\"")
 }
 
-func (a *AnalyzerDatabase) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (a *AnalyzerDatabase) UnmarshalYAML(unmarshal func(any) error) error {
 	// Try to unmarshal as boolean first
 	var b bool
 	if err := unmarshal(&b); err == nil {