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>

frontend/src/pages/api-docs/endpoints.ts

@@ -1277,6 +1277,12 @@ export const sections: readonly Section[] = [
         path: '/panel/api/xray/getXrayResult',
         summary: 'Return the most recent Xray process stdout/stderr output. Useful to check for startup errors or runtime warnings.',
       },
+      {
+        method: 'GET',
+        path: '/panel/api/xray/getGeodataCategories',
+        summary: 'Return every geosite/geoip category found in the .dat files currently present in the Xray bin folder (including custom files added via the Geodata auto-update feature), formatted as ready-to-use routing rule values, e.g. "geosite:youtube" or "ext:geosite_roscom.dat:some-code".',
+        response: '{\n  "success": true,\n  "obj": {\n    "domain": ["geosite:cn", "geosite:youtube"],\n    "ip": ["geoip:cn", "geoip:private"]\n  }\n}',
+      },
       {
         method: 'POST',
         path: '/panel/api/xray/update',