feat: render live text-file embeds in expandable Markdown blocks

Show rendered first/last six-line previews with expand, refresh and retry; bound and deduplicate context-guarded fetches. Verify 2586 tests twice with Node Web Storage compatibility flag, 2 live integration tests, typecheck, Biome and production build.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/features/markdown/types.ts b/src/features/markdown/types.ts
new file mode 100644
index 0000000..cb3fe8d
--- /dev/null
+++ b/src/features/markdown/types.ts
@@ -0,0 +1,13 @@
+import type { TextFileContextResponse, TextFileResponse } from "@dispatch/transport-contract";
+
+export type TextFileState =
+  | { readonly kind: "loading" }
+  | { readonly kind: "error"; readonly message: string }
+  | { readonly kind: "ready"; readonly file: TextFileResponse };
+export interface TextFileClient {
+  subscribe(path: string, listener: (state: TextFileState) => void): () => void;
+  /** Refresh context as well as the live on-disk file. */
+  refresh(path: string): void;
+  dispose(): void;
+}
+export type TextFileContext = TextFileContextResponse;