feat(export-import): add yaml export/import with id upsert for credentials, snippets, and scenarios

- all entities export a kind field (credential/snippet/scenario) for safe type checking on import
- import upserts by id: overwrites if id exists, creates with explicit id otherwise
- scenario export now includes id and step ids; import deletes old steps before recreating
- add GET /:id/export and POST /import endpoints to credential and snippet controllers
- add UuidBadge ui component: shortens uuid to first+last 4 hex chars, tooltip, clipboard copy with animated ClipboardCheck icon pop
- apply UuidBadge across all entity id display sites (detail pages, card footers, table columns)
- add export/import buttons to CredentialsPage, SnippetsPage, CredentialDetailPage, SnippetDetailPage

server/src/scenario/dto/scenario-export.dto.ts

@@ -7,6 +7,7 @@ import {
   IsNotEmpty,
   IsOptional,
   IsString,
+  IsUUID,
   Min,
   ValidateNested,
 } from "class-validator";
@@ -22,10 +23,11 @@ export class ScenarioStepExportDto {
   @IsIn(["login", "exec", "sign"])
   type: StepType;
 
-  @ApiProperty()
+  @ApiPropertyOptional()
+  @IsOptional()
   @IsString()
   @IsNotEmpty()
-  sessionName: string | null;
+  title: string | null;
 
   @ApiPropertyOptional()
   @IsOptional()
@@ -41,6 +43,22 @@ export class ScenarioStepExportDto {
 }
 
 export class ScenarioExportDto {
+  @ApiPropertyOptional()
+  @IsOptional()
+  @IsIn(["scenario"])
+  kind?: "scenario";
+
+  @ApiPropertyOptional()
+  @IsOptional()
+  @IsUUID()
+  id?: string;
+
+  @ApiPropertyOptional()
+  @IsOptional()
+  @IsString()
+  @IsNotEmpty()
+  title?: string;
+
   @ApiProperty()
   @IsString()
   @IsNotEmpty()