Unify manual topology roots with UME World: auto root map, and fix empty UME canvas.

Top-level folders are nav-only with a unique system root map; UI drops custom/extra L2 creates. Batched dock-to-Fabric apply avoids PG lock OOM so World NEs can render, with subtree region counts restored.

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

web/src/i18n/en.ts

@@ -1394,7 +1394,11 @@ const en = {
     maps: "Maps",
     tree: "Topology tree",
     treeLoading: "Loading tree…",
-    treeHint: "Regions hold maps you create; open a map to edit the canvas.",
+    graphLoading: "Loading topology…",
+    graphRefreshing: "Refreshing…",
+    canvasEmpty: "No NEs on this map yet",
+    canvasEmptyHint: "Use Add NE, or pick a region that already has devices.",
+    treeHint: "Top level is a Root (nav only); its unique Root Map is the canvas. Open the root map or a sub-region to edit devices.",
     treeSearch: "Search NEs across maps",
     treeSearchPh: "Name / IP",
     treeSearchEmpty: "No matching NEs",
@@ -1402,47 +1406,47 @@ const en = {
     treeSearchNotOnMap: "This NE is not placed on any topology map yet",
     treeSearchViewCount: "{{count}} map(s)",
     treeSearchTruncated: "Showing first 30 of {{total}}",
-    rootName: "Regions",
-    selectRegion: "Select a region",
+    rootName: "Roots",
+    selectRegion: "Select a root or region",
     openMap: "Open map",
-    openRegion: "Open region",
+    openRegion: "Open",
     kindPhysical: "Physical",
     kindCustom: "Custom",
     regionNodeHint: "{{count}}P",
     layerNodeHint: "{{count}} NE(s)",
     layerNodeEmpty: "Click to create & open",
-    rootCanvasHint: "Pick a region from the left tree.",
-    regionCanvasHint: "Open a map to edit devices, or create a custom map.",
-    regionBrowseHint: "Region folder: maps you add. Click to open.",
+    rootCanvasHint: "Pick a root from the left tree.",
+    regionCanvasHint: "Open the root map to edit devices; create sub-regions on that canvas.",
+    regionBrowseHint: "Root folder: unique root map below. Click to open.",
     browserTitle: "Topology folder",
     browserRegionSub: "{{count}} map(s)",
-    browserRegionsSub: "{{count}} region(s)",
-    browserEmptyMaps: "No maps in this region yet.",
+    browserRegionsSub: "{{count}} item(s)",
+    browserEmptyMaps: "No root map under this root yet.",
     addNe: "Add NE",
-    backUp: "Back to region",
-    newRegion: "New region",
-    newRegionName: "New region",
-    newRegionPrompt: "Region name",
+    backUp: "Back",
+    newRegion: "New root",
+    newRegionName: "New root",
+    newRegionPrompt: "Root name",
     newSubRegion: "New sub-region",
     newSubRegionName: "New sub-region",
     newSubRegionPrompt: "Sub-region name",
     subRegionNotOnFlat: "The flat world map has no regions. Create sub-regions on World or a lower-level canvas.",
     worldMapNoDirectNes: "Cannot add NEs on the world map — add them on a sub-region canvas.",
-    subRegionNeedParent: "Open a region canvas first, then create a sub-region.",
-    regionCreated: "Region created",
-    regionDeleted: "Region deleted",
-    deleteRegion: "Delete region",
-    deleteRegionConfirm: "Delete region \"{{name}}\"? Its maps will also be deleted.",
-    renameRegion: "Rename region",
-    renameRegionPrompt: "Region name",
-    regionRenamed: "Region renamed",
-    collapseRegion: "Collapse region",
-    expandRegion: "Expand region",
+    subRegionNeedParent: "Open a root map or region canvas first, then create a sub-region.",
+    regionCreated: "Created",
+    regionDeleted: "Deleted",
+    deleteRegion: "Delete",
+    deleteRegionConfirm: "Delete \"{{name}}\"? Its maps will also be deleted.",
+    renameRegion: "Rename",
+    renameRegionPrompt: "Name",
+    regionRenamed: "Renamed",
+    collapseRegion: "Collapse",
+    expandRegion: "Expand",
     newCustom: "Custom map",
     newCustomName: "Custom topology",
     newCustomPrompt: "Custom map name",
-    folderHint: "Regions group maps. After creating a region, add a physical or custom map yourself.",
-    folderHintShort: "Region folder",
+    folderHint: "Creating a root auto-creates its unique root map. Add sub-regions on that canvas.",
+    folderHintShort: "Root folder",
     outsidePeers: "{{count}} outside peer(s) linked but not on this map",
     projectNeighbors: "Project neighbors",
     projectedNeighbors: "Projected {{count}} neighbor(s) onto the map",
@@ -1467,7 +1471,7 @@ const en = {
     renamed: "Topology map renamed",
     deleteMap: "Delete map",
     deleteMapConfirm: "Delete map \"{{name}}\"? Nodes and edges will be removed.",
-    emptyMaps: "No regions yet. Create a region first.",
+    emptyMaps: "No roots yet. Create a root first.",
     palette: "NE library",
     paletteHint: "Select multiple to add in batch, or drag one onto the canvas",
     paletteDragHint: "Drag onto canvas to add",