fix(app): autocomplete configured references (#34308)

Co-authored-by: Brendan Allan <14191578+Brendonovich@users.noreply.github.com>
Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: Brendan Allan <git@brendonovich.dev>

packages/app/src/context/prompt.tsx

@@ -27,6 +27,8 @@ export interface FileAttachmentPart extends PartBase {
   type: "file"
   path: string
   selection?: FileSelection
+  mime?: string
+  filename?: string
 }
 
 export interface AgentPart extends PartBase {
@@ -73,7 +75,13 @@ function isPartEqual(partA: ContentPart, partB: ContentPart) {
     case "text":
       return partB.type === "text" && partA.content === partB.content
     case "file":
-      return partB.type === "file" && partA.path === partB.path && isSelectionEqual(partA.selection, partB.selection)
+      return (
+        partB.type === "file" &&
+        partA.path === partB.path &&
+        partA.mime === partB.mime &&
+        partA.filename === partB.filename &&
+        isSelectionEqual(partA.selection, partB.selection)
+      )
     case "agent":
       return partB.type === "agent" && partA.name === partB.name
     case "image":