Auto-commit extra files (#197)

Whenever Dyad does a commit from a proposal, it will automatically amend
the commit with outside changes (e.g. made outside of Dyad).

This helps avoid a lot of user confusion, e.g.
https://github.com/dyad-sh/dyad/issues/187

https://www.reddit.com/r/dyadbuilders/comments/1kjysc0/error_pushing_images/

Edge cases:
If a user adds a file outside of Dyad, and then they hit retry, it will
revert these outside changes, but it's still technically in the version
history, so I think it's OK. This should also be a pretty unusual
situation.

Fixes #164 
Fixes #187

src/ipc/ipc_client.ts

@@ -26,6 +26,7 @@ import type {
   CreateCustomLanguageModelProviderParams,
   CreateCustomLanguageModelParams,
   DoesReleaseNoteExistParams,
+  ApproveProposalResult,
 } from "./ipc_types";
 import type { ProposalResult } from "@/lib/schemas";
 import { showError } from "@/lib/toast";
@@ -601,9 +602,7 @@ export class IpcClient {
   }: {
     chatId: number;
     messageId: number;
-  }): Promise<{
-    uncommittedFiles?: string[];
-  }> {
+  }): Promise<ApproveProposalResult> {
     return this.ipcRenderer.invoke("approve-proposal", {
       chatId,
       messageId,