fix(settings): защищать восстановление базы от повторов и смены контекста

shared/api/system-database.test.ts

@@ -38,3 +38,12 @@ test("backup warning header is strict and malformed metadata preserves valid arc
   }
  }finally{globalThis.fetch=original}
 })
+
+test("restore dispatch checkpoint runs only after local validation and immediately before POST",async()=>{
+ const original=globalThis.fetch;const calls:string[]=[];try{
+  globalThis.fetch=async()=>{calls.push("POST");return Response.json({ok:true})}
+  const options={onDispatch:()=>calls.push("checkpoint")}
+  await assert.rejects(restoreSystemDatabaseBackup("https://backend.test",new File(["wrong"],"wrong.dump"),options));assert.deepEqual(calls,[])
+  await restoreSystemDatabaseBackup("https://backend.test",dump,options);assert.deepEqual(calls,["checkpoint","POST"])
+ }finally{globalThis.fetch=original}
+})