fix(core): resolve prompt attachment mime types

packages/schema/src/index.ts

@@ -24,4 +24,5 @@ export { PtyTicket } from "./pty-ticket"
 export { Question } from "./question"
 export { Workspace } from "./workspace"
 export { Prompt, Source, FileAttachment, AgentAttachment } from "./prompt"
+export { PromptInput } from "./prompt-input"
 export * from "./schema"

packages/schema/src/prompt-input.ts

@@ -0,0 +1,26 @@
+export * as PromptInput from "./prompt-input"
+
+import { Schema } from "effect"
+import { AgentAttachment, Source } from "./prompt"
+import { optional, statics } from "./schema"
+
+export interface FileAttachment extends Schema.Schema.Type<typeof FileAttachment> {}
+export const FileAttachment = Schema.Struct({
+  uri: Schema.String,
+  name: Schema.String.pipe(optional),
+  description: Schema.String.pipe(optional),
+  source: Source.pipe(optional),
+})
+  .annotate({ identifier: "PromptInput.FileAttachment" })
+  .pipe(
+    statics((schema) => ({
+      create: (input: FileAttachment) => schema.make(input),
+    })),
+  )
+
+export interface Prompt extends Schema.Schema.Type<typeof Prompt> {}
+export const Prompt = Schema.Struct({
+  text: Schema.String,
+  files: Schema.Array(FileAttachment).pipe(optional),
+  agents: Schema.Array(AgentAttachment).pipe(optional),
+}).annotate({ identifier: "PromptInput" })