Add guided tours and unify left-to-right hall wall hang.

Visitors walk published tours in a 3D hall with stop notes; curators edit drafts via Tour editor. All galleries (artist, movement, tour) place the first work left of the entrance view and the last on the right.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/locales/en/tours.json

@@ -0,0 +1,28 @@
+{
+  "title": "Guided tours",
+  "popupTitle": "Guided tours",
+  "popupHint": "Choose a curated walkthrough of selected works.",
+  "close": "Close",
+  "loading": "Loading…",
+  "loadFailed": "Failed to load tours",
+  "noPublished": "No published tours yet.",
+  "noTours": "No tours yet. Create one to get started.",
+  "stopCount": "{{count}} stops",
+  "back": "← Back to gallery",
+  "create": "Create",
+  "newTourPlaceholder": "New tour title…",
+  "selectTour": "Select a tour to edit.",
+  "tourTitle": "Title",
+  "tourDescription": "Description",
+  "status": "Status",
+  "draft": "Draft",
+  "published": "Published",
+  "saveMeta": "Save details",
+  "delete": "Delete tour",
+  "confirmDelete": "Delete this tour and all its stops?",
+  "searchPainting": "Search paintings to add…",
+  "saveStops": "Save stops",
+  "remove": "Remove",
+  "stopBodyPlaceholder": "Tour notes for this stop (English)…",
+  "noStops": "No stops yet. Search and add paintings."
+}