feat(scenario): export scenarios as standalone playwright e2e test projects

- Added E2eExportService to package scenarios as plug-and-play zip archives
  containing package.json, playwright.config.ts, test.spec.ts, .env, credentials.json,
  snippets, and referenced scenario files
- Only bundles credentials, snippets, and files actually referenced (directly or
  transitively) by the scenario's steps, reducing archive size
- Exported test runs entirely offline using a context shim that mirrors liqa's API
  (page, getCredential, runSnippet, getScenarioFiles, downloadFile, assert, etc.)
- Added GET /scenarios/:id/export-e2e HTTP endpoint and export_e2e_test MCP tool
- Added getUsedSnippets() endpoint to list snippets referenced by a scenario
- Added "Used Snippets" section on scenario detail page
- Added archiver@^7.0.1 dependency for zip archive creation
- Bumped version to 1.11.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "liqa",
-  "version": "1.10.1",
+  "version": "1.11.0",
   "private": true,
   "workspaces": [
     "server",