refactor: deduplicate utility helpers across the codebase (#23338)

Audited exported helpers in `coderd/util/*`, `testutil`, `cryptorand`,
and friends, then replaced duplicated implementations with canonical
versions.

- **fix: `maps.SortedKeys` generic signature** — value type was
hardcoded to `any`, making it impossible to actually call. Added second
type parameter `V any`. Added table-driven tests with `cmp.Diff`.
- **refactor: replace ad-hoc ptr helpers with `ptr.Ref`** — removed
`int64Ptr`, `stringPtr`, `boolPtr`, `i64ptr`, `strPtr`, `PtrInt32`
across 6 files.
- **refactor: replace local `sortedKeys`/`sortKeys` with
`maps.SortedKeys`** — now that the signature is fixed, scripts can use
it.
- **refactor: replace hand-rolled `capitalize` with
`strings.Capitalize`** — the typegen version was also not UTF-8 safe.

> 🤖 This PR was created with the help of Coder Agents, and was reviewed
by my human. 🧑‍💻

scripts/auditdocgen/main.go

@@ -5,12 +5,12 @@ import (
 	"flag"
 	"log"
 	"os"
-	"sort"
 	"strconv"
 	"strings"
 
 	"golang.org/x/xerrors"
 
+	"github.com/coder/coder/v2/coderd/util/maps"
 	"github.com/coder/coder/v2/enterprise/audit"
 	"github.com/coder/coder/v2/scripts/atomicwrite"
 )
@@ -96,7 +96,7 @@ func readAuditDoc() ([]byte, error) {
 // Writes a markdown table of audit log resources to a buffer
 func updateAuditDoc(doc []byte, auditableResourcesMap AuditableResourcesMap) ([]byte, error) {
 	// We must sort the resources to ensure table ordering
-	sortedResourceNames := sortKeys(auditableResourcesMap)
+	sortedResourceNames := maps.SortedKeys(auditableResourcesMap)
 
 	i := bytes.Index(doc, generatorPrefix)
 	if i < 0 {
@@ -135,7 +135,7 @@ func updateAuditDoc(doc []byte, auditableResourcesMap AuditableResourcesMap) ([]
 		_, _ = buffer.WriteString("|" + readableResourceName + "<br><i>" + auditActionsString + "</i>|<table><thead><tr><th>Field</th><th>Tracked</th></tr></thead><tbody>" + "|")
 
 		// We must sort the field names to ensure sub-table ordering
-		sortedFieldNames := sortKeys(auditableResourcesMap[resourceName])
+		sortedFieldNames := maps.SortedKeys(auditableResourcesMap[resourceName])
 
 		for _, fieldName := range sortedFieldNames {
 			isTracked := auditableResourcesMap[resourceName][fieldName]
@@ -153,12 +153,3 @@ func updateAuditDoc(doc []byte, auditableResourcesMap AuditableResourcesMap) ([]
 func writeAuditDoc(doc []byte) error {
 	return atomicwrite.File(auditDocFile, doc)
 }
-
-func sortKeys[T any](stringMap map[string]T) []string {
-	var keyNames []string
-	for key := range stringMap {
-		keyNames = append(keyNames, key)
-	}
-	sort.Strings(keyNames)
-	return keyNames
-}

scripts/metricsdocgen/main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/prometheus/common/expfmt"
 	"golang.org/x/xerrors"
 
+	"github.com/coder/coder/v2/coderd/util/maps"
 	"github.com/coder/coder/v2/scripts/atomicwrite"
 )
 
@@ -176,7 +177,7 @@ func updatePrometheusDoc(doc []byte, metricFamilies []*dto.MetricFamily) ([]byte
 		}
 
 		if len(labels) > 0 {
-			_, _ = buffer.WriteString(strings.Join(sortedKeys(labels), " "))
+			_, _ = buffer.WriteString(strings.Join(maps.SortedKeys(labels), " "))
 		}
 
 		_, _ = buffer.WriteString(" |\n")
@@ -190,12 +191,3 @@ func updatePrometheusDoc(doc []byte, metricFamilies []*dto.MetricFamily) ([]byte
 func writePrometheusDoc(doc []byte) error {
 	return atomicwrite.File(prometheusDocFile, doc)
 }
-
-func sortedKeys(m map[string]struct{}) []string {
-	var keys []string
-	for k := range m {
-		keys = append(keys, k)
-	}
-	sort.Strings(keys)
-	return keys
-}

scripts/typegen/main.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/coder/coder/v2/coderd/rbac"
 	"github.com/coder/coder/v2/coderd/rbac/policy"
+	utilstrings "github.com/coder/coder/v2/coderd/util/strings"
 	"github.com/coder/coder/v2/codersdk"
 )
 
@@ -131,15 +132,11 @@ func generateCountries() ([]byte, error) {
 func pascalCaseName[T ~string](name T) string {
 	names := strings.Split(string(name), "_")
 	for i := range names {
-		names[i] = capitalize(names[i])
+		names[i] = utilstrings.Capitalize(names[i])
 	}
 	return strings.Join(names, "")
 }
 
-func capitalize(name string) string {
-	return strings.ToUpper(string(name[0])) + name[1:]
-}
-
 type Definition struct {
 	policy.PermissionDefinition
 	Type string
@@ -226,7 +223,7 @@ func generateRbacObjects(templateSource string) ([]byte, error) {
 	var errorList []error
 	var x int
 	tpl, err := template.New("object.gotmpl").Funcs(template.FuncMap{
-		"capitalize":     capitalize,
+		"capitalize":     utilstrings.Capitalize,
 		"pascalCaseName": pascalCaseName[string],
 		"actionsList": func() []ActionDetails {
 			return actionList