feat(templates): add shareable flow templates with install and auto-update

[realcodesiman]

Summary

• Lets a workspace publish a flow (with its folder manifest) as a shareable template, protected by a share token, accessible at /t/[shareToken]
• Lets other workspaces install a published template into their own space, remapping references (flows, folders, keywords) so the installed copy is self-contained
• Adds optional auto-update: installations can stay in sync with the source template, tracked via TemplateInstallation/TemplateInstalledResource, with a worker handler (install-template.ts) doing the install/update work off the request path
• New templates management surfaces in the builder: space/[workspaceId]/templates (create/manage templates) and templates/installs (manage/reinstall/toggle auto-update per installation)

Changes

• Database: new template, templateInstallation, templateInstalledResource schema/partials/relations + two migrations (20260817114301_add_template, 20260818081114_add_template_install_folder_and_autoupdate)
• Business: packages/business/src/template/ (template + install services), extracted integration-webchat/service.ts
• Flow config import/export: new reference-fields.ts, remap.ts, template-schema.ts to remap flow/folder/keyword references between source and installed copies
• Worker: new install-template job handler wired into worker-config queues and apps/worker/src/default/worker.ts
• Builder: new features/templates/ feature module, app/space/[workspaceId]/templates/ pages, public app/t/[shareToken]/ share page, proxy.ts/routers/index.ts updates for the public route, i18n strings across all locales
• Tests: packages/business/__tests__/template-*.test.ts, packages/flow-config/__tests__/remap.test.ts, template-export-schema.test.ts

Test plan

• pnpm lint
• pnpm --filter builder check-types
• pnpm --filter worker check-types
• pnpm --filter @chatbotx.io/business check-types
• pnpm --filter @chatbotx.io/flow-config check-types
• pnpm --filter @chatbotx.io/database db:migrate (manual, after review)
• Manual: create a template from a flow, install it into another workspace, verify auto-update toggle and reinstall flow