fix(studio): the travel panel builds its tiles with the book engine's factories

Figures, countries, maps and marks placed from the panel are the elements the
assistant adds, built by the shared factories; the panel keeps only their
placement. A trip map no longer carries the whole journey's trail, switching a
map's scope re-cuts it the way the engine does and clears the roads of the old
legs, and switching back to the whole journey restores the trail.

client/scripts/eslint-baseline.json

@@ -6,7 +6,7 @@
     "complexity": 226,
     "@typescript-eslint/no-explicit-any": 146,
     "trek/no-swallowed-catch": 131,
-    "max-params": 34,
+    "max-params": 33,
     "trek/store-without-selector": 67,
     "react-hooks/refs": 557,
     "react-hooks/set-state-in-effect": 195,
@@ -14,7 +14,7 @@
     "react-hooks/exhaustive-deps": 116,
     "@typescript-eslint/no-unused-vars": 126,
     "react-hooks/immutability": 28,
-    "max-lines-per-function": 133,
+    "max-lines-per-function": 132,
     "react-hooks/static-components": 78,
     "react-hooks/preserve-manual-memoization": 12,
     "no-useless-assignment": 7,

client/scripts/theme-baseline.json

@@ -105,7 +105,6 @@
   "components/Studio/StudioInspector.tsx": 2,
   "components/Studio/StudioShell.tsx": 2,
   "components/Studio/StudioSidebar.tsx": 2,
-  "components/Studio/StudioTravelPanel.tsx": 1,
   "components/Studio/TravelElements.tsx": 5,
   "components/Studio/printSheets.ts": 5,
   "components/SystemNotices/ReleaseNoticeVisuals.tsx": 4,