feat(scenarios): add step title, scenario credentials, and environment context in executor

- add nullable title column to scenario steps; exposed in create/edit forms and step table
- add scenario-credential join (many-to-many with CredentialEntity) with CRUD endpoints
- expose environment URLs in code executor helpers via helpers.env and helpers.getEnvUrl()
- resolve and cache environment per run from the login step's environmentName in scheduler
- add section spacing and step table title column to ScenarioDetailPage

server/src/credential/credential.controller.ts

@@ -0,0 +1,66 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  HttpCode,
+  Param,
+  ParseIntPipe,
+  Patch,
+  Post,
+  Query,
+} from "@nestjs/common";
+import { ApiOperation, ApiResponse, ApiTags } from "@nestjs/swagger";
+import { CredentialService } from "./credential.service";
+import { CreateCredentialDto } from "./dto/create-credential.dto";
+import { UpdateCredentialDto } from "./dto/update-credential.dto";
+import { PaginationQueryDto } from "../common/dto/pagination.dto";
+import { CredentialOrderBy } from "./credential.service";
+
+@ApiTags("credentials")
+@Controller("credentials")
+export class CredentialController {
+  constructor(private readonly credentialService: CredentialService) {}
+
+  @Post()
+  @ApiOperation({ summary: "Create a new credential" })
+  @ApiResponse({ status: 201, description: "Credential created" })
+  create(@Body() dto: CreateCredentialDto) {
+    return this.credentialService.create(dto);
+  }
+
+  @Get()
+  @ApiOperation({ summary: "List all credentials (paginated)" })
+  @ApiResponse({ status: 200, description: "Paginated credentials" })
+  findAll(@Query() query: PaginationQueryDto<CredentialOrderBy>) {
+    return this.credentialService.findAll(query);
+  }
+
+  @Get(":id")
+  @ApiOperation({ summary: "Get credential by ID" })
+  @ApiResponse({ status: 200, description: "Credential record" })
+  @ApiResponse({ status: 404, description: "Credential not found" })
+  findOne(@Param("id", ParseIntPipe) id: number) {
+    return this.credentialService.findOne(id);
+  }
+
+  @Patch(":id")
+  @ApiOperation({ summary: "Update a credential" })
+  @ApiResponse({ status: 200, description: "Credential updated" })
+  @ApiResponse({ status: 404, description: "Credential not found" })
+  update(
+    @Param("id", ParseIntPipe) id: number,
+    @Body() dto: UpdateCredentialDto,
+  ) {
+    return this.credentialService.update(id, dto);
+  }
+
+  @Delete(":id")
+  @HttpCode(204)
+  @ApiOperation({ summary: "Delete a credential" })
+  @ApiResponse({ status: 204, description: "Credential deleted" })
+  @ApiResponse({ status: 404, description: "Credential not found" })
+  remove(@Param("id", ParseIntPipe) id: number) {
+    return this.credentialService.remove(id);
+  }
+}