ENG-2595 (#3976)

* feat: implement railway secret sync

* fix: railway sync config

* feat: add documentation on railway

* fix: undo mock on-prem change

* lint: fix

* fix: cleanup railway integration

* fix: retry and doc images

* fix: sync fields

* fix: query typo

* Update docs/docs.json

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

backend/src/server/routes/v1/app-connection-routers/app-connection-router.ts

@@ -71,6 +71,10 @@ import {
   PostgresConnectionListItemSchema,
   SanitizedPostgresConnectionSchema
 } from "@app/services/app-connection/postgres";
+import {
+  RailwayConnectionListItemSchema,
+  SanitizedRailwayConnectionSchema
+} from "@app/services/app-connection/railway";
 import {
   RenderConnectionListItemSchema,
   SanitizedRenderConnectionSchema
@@ -123,7 +127,8 @@ const SanitizedAppConnectionSchema = z.union([
   ...SanitizedGitLabConnectionSchema.options,
   ...SanitizedCloudflareConnectionSchema.options,
   ...SanitizedBitbucketConnectionSchema.options,
-  ...SanitizedZabbixConnectionSchema.options
+  ...SanitizedZabbixConnectionSchema.options,
+  ...SanitizedRailwayConnectionSchema.options
 ]);
 
 const AppConnectionOptionsSchema = z.discriminatedUnion("app", [
@@ -157,7 +162,8 @@ const AppConnectionOptionsSchema = z.discriminatedUnion("app", [
   GitLabConnectionListItemSchema,
   CloudflareConnectionListItemSchema,
   BitbucketConnectionListItemSchema,
-  ZabbixConnectionListItemSchema
+  ZabbixConnectionListItemSchema,
+  RailwayConnectionListItemSchema
 ]);
 
 export const registerAppConnectionRouter = async (server: FastifyZodProvider) => {