fix(graph-view): match string and object link endpoints in applyMutation

While Activity hides the tool, mutations still update graph.data but
force-graph never rewrites link endpoints from ids to node objects.
Filters that only read endpoint.id left those string links in place,
so later updates/disappears could leave stale or duplicate edges.

Author: cursoragent

plugins/sanity-plugin-graph-view/src/tool/GraphView.test.tsx

@@ -334,4 +334,26 @@ describe('applyMutation', () => {
     expect(next).toBe(state)
     expect(docNode).toBeUndefined()
   })
+
+  // While Activity hides the tool, force-graph never rewrites string endpoints to node objects.
+  // Mutations still chain through applyMutation, so filters must match both shapes.
+  test('replaces string-endpoint links when references change before force-graph rewrites them', () => {
+    const state = {documents: [author, post], graph: new GraphData([author, post])}
+    expect(state.graph.data.links).toEqual([{source: 'b', target: 'a'}])
+
+    const other = {...stamps, _id: 'c', _type: 'author', title: 'C'} as SanityDocument
+    const withOther = applyMutation(state, mutation('appear', 'c', other)).next
+    const doc = {...stamps, _id: 'b', _type: 'post', title: 'B', author: {_ref: 'c'}}
+    const {next} = applyMutation(withOther, mutation('update', 'b', doc))
+
+    expect(next.graph.data.links).toEqual([{source: 'b', target: 'c'}])
+  })
+
+  test('removes string-endpoint links when a document disappears before force-graph rewrites them', () => {
+    const state = {documents: [author, post], graph: new GraphData([author, post])}
+    const {next} = applyMutation(state, mutation('disappear', 'b'))
+
+    expect(next.graph.data.links).toEqual([])
+    expect(next.graph.data.nodes.map((n: {id: string}) => n.id)).toEqual(['a'])
+  })
 })

plugins/sanity-plugin-graph-view/src/tool/GraphView.tsx

@@ -79,6 +79,11 @@ function stripDraftId(id: string) {
   return id.replace(/^drafts\./, '')
 }
 
+/** force-graph replaces string endpoints with node objects; mutations while hidden leave strings. */
+function linkEndpointId(endpoint: string | {id: string}): string {
+  return typeof endpoint === 'object' ? endpoint.id : endpoint
+}
+
 function deduplicateDrafts(docs: SanityDocument[]) {
   const deduped: Record<string, SanityDocument> = {}
   for (const doc of docs) {
@@ -219,7 +224,7 @@ export function applyMutation(
     let graphChanged = !dequal(oldRefs, newRefs)
     if (graphChanged) {
       newGraph.data.links = newGraph.data.links
-        .filter((l: any) => l.source.id !== doc._id)
+        .filter((l: any) => linkEndpointId(l.source) !== doc._id)
         .concat(newRefs.map((ref) => ({source: doc._id, target: ref})))
     }
 
@@ -242,7 +247,7 @@ export function applyMutation(
 
     const newGraph = graph.clone()
     newGraph.data.links = newGraph.data.links.filter(
-      (l: any) => l.source.id !== docId && l.target.id !== docId,
+      (l: any) => linkEndpointId(l.source) !== docId && linkEndpointId(l.target) !== docId,
     )
     newGraph.data.nodes = newGraph.data.nodes.filter((n: any) => n.id !== docId)