refactor: replace custom geo manager with Xray-core native geodata auto-update

Remove the panel-side custom geo download feature (service, controller,
/panel/api/custom-geo/* endpoints, CustomGeoResource model, UI tab) in
favor of Xray-core's native geodata section
(https://xtls.github.io/config/geodata.html).

- pass the top-level "geodata" key through xray.Config so it survives
  the template round-trip into the generated config
- add a Geodata Auto-Update section to the Xray Updates modal that
  edits geodata (cron schedule, download outbound, asset list) in the
  config template and restarts Xray on save
- previously downloaded geo files in the bin folder keep working in
  ext: routing rules; the orphaned custom_geo_resources table is left
  in place so existing source URLs stay recoverable

frontend/src/generated/zod.ts

@@ -280,19 +280,6 @@ export const ClientTrafficSchema = z.object({
 });
 export type ClientTraffic = z.infer<typeof ClientTrafficSchema>;
 
-export const CustomGeoResourceSchema = z.object({
-  alias: z.string(),
-  createdAt: z.number().int(),
-  id: z.number().int(),
-  lastModified: z.string(),
-  lastUpdatedAt: z.number().int(),
-  localPath: z.string(),
-  type: z.string(),
-  updatedAt: z.number().int(),
-  url: z.string(),
-});
-export type CustomGeoResource = z.infer<typeof CustomGeoResourceSchema>;
-
 export const FallbackParentInfoSchema = z.object({
   masterId: z.number().int(),
   path: z.string().optional(),