Harden topology editor save/discover flow and edge editing.

Guard unsaved changes, cancel discovery, block invalid links, preserve discovered_at on PUT, and normalize interface names for discovery keys.

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

web/src/i18n/en.ts

@@ -891,6 +891,8 @@ const en = {
     paletteHint: "Click or drag onto the canvas",
     filterPh: "Filter name / IP",
     save: "Save",
+    saveDirty: "Save *",
+    unsavedConfirm: "You have unsaved changes. Discard and switch maps?",
     saving: "Saving…",
     saved: "Topology saved",
     discover: "Discover all links",
@@ -900,6 +902,10 @@ const en = {
     discoverFail: "Discovery failed: {{detail}}",
     discoverOneNeedNe: "This node is not linked to a scannable NE",
     selectMap: "Select or create a topology map",
+    renameNode: "Rename",
+    renameNodePrompt: "Node display name",
+    sourcePort: "Local port",
+    targetPort: "Remote port",
     canvasHint:
       "Use toolbar modes (select/pan/drag/connect), box-select, and layout. Blue dashed=discovered, red=missing. Shortcuts V/H/A/C, Ctrl+Z undo.",
     selected: "Selected",
@@ -973,6 +979,7 @@ const en = {
     paletteLoading: "Loading…",
     discoverReport: "Discovery progress",
     discoverClose: "Close",
+    discoverCancel: "Cancel discovery",
     discoverProgress: "Scanning {{count}} managed NE(s) on the map (serial LLDP; please wait)…",
     discoverProgressLive: "Scanning {{index}}/{{total}}: {{name}}",
     discoverSummary: "Scanned {{scanned}} · added {{added}} · updated {{updated}} · missing {{stale}} · failed {{failed}}",