refactor(auth): remove keys auth module and align tests

- remove server auth module and client keys page/routes/api to simplify flow

- update mcp and scenario tests to match uuid routes and step schema

server/src/scenario/scenario.service.ts

@@ -334,7 +334,6 @@ export class ScenarioService {
       name: scenario.name,
       steps: scenario.steps.map((s) => ({
         order: s.order,
-        type: s.type,
         title: s.title,
         execCode: s.execCode,
         validateCode: s.validateCode,
@@ -367,7 +366,6 @@ export class ScenarioService {
         this.stepRepo.create({
           scenarioId: scenario.id,
           order: s.order,
-          type: s.type,
           title: s.title ?? null,
           execCode: s.execCode ?? null,
           validateCode: s.validateCode ?? null,