feat(xray): autocomplete geosite/geoip categories in the routing rule editor

Writing a routing rule today means remembering exact geosite:/geoip:/
ext:file:code syntax by hand, with no way to discover what categories
actually exist in the .dat files sitting in the bin folder -- including
custom ones like geosite_roscom.dat added via the Geodata auto-update
feature. The Domain/IP fields in the rule editor now suggest categories
as you type (e.g. "you" -> "geosite:youtube"), built live from whatever
.dat files are actually on disk, while still accepting any free-typed
value exactly as before.

Backend: GET /panel/api/xray/getGeodataCategories scans the bin folder,
parses matched geosite*/geoip*.dat files via xray-core's own exported
protobuf types, and formats each category as the exact rule syntax
xray-core's parser accepts -- geosite:/geoip: for the default files,
ext:<file>:<code> for anything else (there's no shorthand for custom
files). Cached in memory keyed by each file's (name, size, modTime) so
a request-time scan is cheap until a file actually changes.

Frontend: the Domain/IP inputs become Select "tags" fields fed by a new
useGeodataCategories() query hook, with an explicit substring filter so
"you" matches "geosite:youtube" (not a prefix). The array<->CSV-string
adapter lives entirely at the FormField transform boundary, so the
underlying form schema and saved rule shape are unchanged.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/web/service/xray_setting.go

@@ -7,6 +7,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/mhsanaei/3x-ui/v3/internal/util/common"
 	"github.com/mhsanaei/3x-ui/v3/internal/xray"
@@ -16,6 +17,13 @@ import (
 // It handles validation and storage of Xray template configurations.
 type XraySettingService struct {
 	SettingService
+
+	// geodataMu/geodataCache back GetGeodataCategories' in-memory cache (see
+	// xray_setting_geodata.go), keyed by the (name, size, modTime)
+	// fingerprint of the geosite*/geoip*.dat files currently present in
+	// config.GetBinFolderPath().
+	geodataMu    sync.Mutex
+	geodataCache *geodataCategoryCache
 }
 
 const (