feat(builder): redesign marketplace builder experience and navigation

Renamed the experience consistently to Marketplace Builder everywhere
visible (page title/subtitle, breadcrumbs, sidebar, dashboard quick
action/shortcut copy) - internal ProjectEditor class/selector names
kept as-is to avoid regressions. builder.title/subtitle no longer say
'bootstrap-config editing surface' to end users.

New business-oriented IA (builder-groups.model.ts): 12 existing
ProjectEditorSectionIds regrouped into 8 groups (Marketplace, Branding
and Design, Homepage, Content, Languages, Marketplace Features,
Navigation and Search, Preview) - every existing section mapped to
exactly one group, none dropped, no group points at a page that
doesn't exist.

New Builder landing page at /edit (was a redirect straight into the
General form): readiness percent, recommended next step, one overview
card per group (purpose + real complete/in-progress/not-started/unknown
status, icon+text never color-alone), a Marketplace Readiness
checklist, quick links. All derived from real facade/schema signals
(required-field fill state, modifiedSections, staticPages, catalog
counts via BackofficeDataService) or explicitly marked unknown
(the "preview reviewed" check has no tracking - shown as unknown,
never guessed).

Section pages (/edit/:section) now share one consistent header:
breadcrumb (Builder > Group > Section), draft/published + modified
badges, and a contextual help panel (what is this / where visible /
what happens if you skip it) sourced per group. Sidebar nav rewritten
as grouped, icon-led sections with per-section and per-group status
indicators; layout converted from a top pill-tab bar to a responsive
sidebar (desktop 280px, tablet 72px icon rail, mobile drawer with
Escape-to-close), matching the Sprint 1 admin shell pattern. Section
form components themselves untouched.

Routes: 'edit' is now its own landing route instead of redirecting to
'edit/general'; /builder and /project-editor redirect to 'edit'.
Sprint 1/2 destinations that pointed at edit/general now point at the
new edit landing page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/translations.ts

@@ -683,6 +683,83 @@ export interface Translations {
     linkLabelDesc: string;
     linkUrlDesc: string;
     linkVisibleDesc: string;
+    appName: string;
+    breadcrumbRoot: string;
+    statusComplete: string;
+    statusInProgress: string;
+    statusNotStarted: string;
+    statusUnknown: string;
+    draftBadge: string;
+    publishedBadge: string;
+    modifiedBadge: string;
+    helpToggleShow: string;
+    helpToggleHide: string;
+    helpWhatIsThis: string;
+    helpWhySkip: string;
+    helpWhereVisible: string;
+    helpWhatIfSkip: string;
+    helpWhenReturn: string;
+    openSidebar: string;
+    closeSidebar: string;
+    overviewTitle: string;
+    overviewSubtitle: string;
+    overviewReadinessLabel: string;
+    overviewReadinessHint: string;
+    overviewNextStepLabel: string;
+    overviewNextStepFallback: string;
+    overviewQuickLinksTitle: string;
+    overviewSectionsTitle: string;
+    overviewOpenSection: string;
+    overviewReadinessTitle: string;
+    readinessLogoUploaded: string;
+    readinessHomepageConfigured: string;
+    readinessThemeConfigured: string;
+    readinessLanguagesConfigured: string;
+    readinessContentPagesAdded: string;
+    readinessPreviewReviewed: string;
+    readinessPublished: string;
+    readinessCategoriesExist: string;
+    readinessProductsExist: string;
+    groupMarketplaceLabel: string;
+    groupMarketplaceDescription: string;
+    groupMarketplacePurpose: string;
+    groupMarketplaceWhere: string;
+    groupMarketplaceSkip: string;
+    groupBrandingLabel: string;
+    groupBrandingDescription: string;
+    groupBrandingPurpose: string;
+    groupBrandingWhere: string;
+    groupBrandingSkip: string;
+    groupHomepageLabel: string;
+    groupHomepageDescription: string;
+    groupHomepagePurpose: string;
+    groupHomepageWhere: string;
+    groupHomepageSkip: string;
+    groupContentLabel: string;
+    groupContentDescription: string;
+    groupContentPurpose: string;
+    groupContentWhere: string;
+    groupContentSkip: string;
+    groupLanguagesLabel: string;
+    groupLanguagesDescription: string;
+    groupLanguagesPurpose: string;
+    groupLanguagesWhere: string;
+    groupLanguagesSkip: string;
+    groupFeaturesLabel: string;
+    groupFeaturesDescription: string;
+    groupFeaturesPurpose: string;
+    groupFeaturesWhere: string;
+    groupFeaturesSkip: string;
+    groupNavigationLabel: string;
+    groupNavigationDescription: string;
+    groupNavigationPurpose: string;
+    groupNavigationWhere: string;
+    groupNavigationSkip: string;
+    groupPreviewLabel: string;
+    groupPreviewDescription: string;
+    groupPreviewPurpose: string;
+    groupPreviewWhere: string;
+    groupPreviewSkip: string;
   };
   dashboard: {
     title: string;