Add index when creating entries through the api

src/core/Graph.ts

@@ -103,10 +103,12 @@ export class GraphRealm implements GraphRealmApi {
     if (Type.isType(select)) select = select().first()
     const selection = createSelection(select)
     serializeSelection(this.#targets, selection)
-    return this.#resolver.resolve({
-      ...this.#params,
-      selection
-    })
+    return (
+      (await this.#resolver.resolve({
+        ...this.#params,
+        selection
+      })) ?? null
+    )
   }
 
   get<S extends Projection | Type>(select: S): Promise<Projection.InferOne<S>>

src/core/Transaction.ts

@@ -23,6 +23,7 @@ import {
   workspaceMediaDir
 } from './util/EntryFilenames.js'
 import {createEntryRow, entryParentPaths} from './util/EntryRows.js'
+import {generateKeyBetween} from './util/FractionalIndexing.js'
 import {basename, extname, join, normalize} from './util/Paths.js'
 import {slugify} from './util/Slugs.js'
 
@@ -276,7 +277,13 @@ export class CreateOperation<Definition> extends Operation {
       : partial.parent
       ? cms.graph.preferPublished.get(Entry({entryId: partial.parent}))
       : undefined)
-    return createEntry(cms.config, type, partial, parent)
+    const previousIndex = await cms.graph.preferPublished.maybeGet(
+      Entry({parent: parent?.entryId ?? null})
+        .select(Entry.index)
+        .orderBy(Entry.index.desc())
+    )
+    const index = generateKeyBetween(previousIndex, null)
+    return createEntry(cms.config, type, {...partial, index}, parent)
   }
 
   constructor(