Blank root panel, asset form as a modal, and a dedicated Statuses page

- Main panel is now blank at the top level ("Select a folder or asset
  from the tree") instead of showing a dashboard - browsing happens in
  the tree, the panel only shows something once you click into it.
  Removed the now-dead DashboardStats/Stats() machinery it depended on.
- Add/Edit Asset no longer takes over the main panel; it opens in
  #assetModal instead; asset_form.html was trimmed down to just the form
  (no more breadcrumb/panel wrapper) since the modal chrome provides the
  title and footer buttons now. The dynamic item-type-fields and submit
  listeners moved from #main-panel's delegation to the modal element's.
- Statuses split out of the General settings page into its own
  /settings/statuses page and sub-nav entry, alongside General, Item
  Types, and Users.

internal/web/handlers_inventory.go

@@ -1,7 +1,6 @@
 package web
 
 import (
-	"context"
 	"net/http"
 
 	"inventree/internal/assets"
@@ -12,7 +11,6 @@ import (
 type InventoryPageData struct {
 	User      *models.User
 	Tree      []models.TreeNode
-	Root      *RootPanelData
 	ItemTypes []models.ItemType
 	Statuses  []models.Status
 }
@@ -31,11 +29,6 @@ func (a *App) handleInventoryPage(w http.ResponseWriter, r *http.Request) {
 		writeErr(w, http.StatusInternalServerError, err.Error())
 		return
 	}
-	root, err := a.rootPanelData(ctx)
-	if err != nil {
-		writeErr(w, http.StatusInternalServerError, err.Error())
-		return
-	}
 	itemTypes, err := a.ItemTypes.List(ctx, false)
 	if err != nil {
 		writeErr(w, http.StatusInternalServerError, err.Error())
@@ -48,7 +41,7 @@ func (a *App) handleInventoryPage(w http.ResponseWriter, r *http.Request) {
 	}
 
 	a.Render(w, http.StatusOK, "inventory", InventoryPageData{
-		User: u, Tree: tree, Root: root, ItemTypes: itemTypes, Statuses: statusList,
+		User: u, Tree: tree, ItemTypes: itemTypes, Statuses: statusList,
 	})
 }
 
@@ -112,39 +105,13 @@ func (a *App) handleTreeCollapseAll(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusNoContent)
 }
 
-// RootPanelData backs the main panel when nothing is selected: the virtual
-// "Inventory" root, showing top-level folders, unfiled assets, and the
-// small dashboard.
-type RootPanelData struct {
-	Folders       []models.Folder
-	UnfiledAssets []models.Asset
-	UnfiledTotal  int
-	Stats         *assets.DashboardStats
-}
-
-func (a *App) rootPanelData(ctx context.Context) (*RootPanelData, error) {
-	folderList, err := a.Folders.Children(ctx, nil)
-	if err != nil {
-		return nil, err
-	}
-	unfiled, total, err := a.Assets.List(ctx, assets.ListFilter{FolderSet: true, FolderID: nil, Page: 1, PageSize: 50})
-	if err != nil {
-		return nil, err
-	}
-	stats, err := a.Assets.Stats(ctx)
-	if err != nil {
-		return nil, err
-	}
-	return &RootPanelData{Folders: folderList, UnfiledAssets: unfiled, UnfiledTotal: total, Stats: stats}, nil
-}
-
+// handlePanelRoot backs the main panel when nothing is selected. It is
+// intentionally blank (no dashboard/summary) - the panel only shows
+// something once a folder or asset is actually clicked; browsing happens
+// in the tree. The fragment still carries a data-panel-type="root" hook so
+// right-click still offers "New Folder" / "Add Asset" / import / export.
 func (a *App) handlePanelRoot(w http.ResponseWriter, r *http.Request) {
-	data, err := a.rootPanelData(r.Context())
-	if err != nil {
-		writeErr(w, http.StatusInternalServerError, err.Error())
-		return
-	}
-	a.RenderFragment(w, http.StatusOK, "panel_root", data)
+	a.RenderFragment(w, http.StatusOK, "panel_root", nil)
 }
 
 // FolderPanelData backs the main panel when a folder is selected.