Deep link: add prompt (#1669)

Example:
open
"dyad://add-prompt?data=eyJ0aXRsZSI6IlRlc3QgUHJvbXB0IiwiZGVzY3JpcHRpb24iOiJBIHRlc3QgcHJvbXB0IGZyb20gZGVlcCBsaW5rIiwiY29udGVudCI6IlRoaXMgaXMgdGhlIGNvbnRlbnQgb2YgdGhlIHByb21wdC4ifQ%3D%3D"

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Adds dyad://add-prompt deep link that navigates to Library and opens a
prefilled Create Prompt dialog from base64 JSON.
> 
> - **Deep Link Handling**
> - Parse `dyad://add-prompt?data=<base64-json>` in `src/main.ts`;
validate with `AddPromptDataSchema` and send `deep-link-received` with
payload.
> - Extend `DeepLinkContext` to navigate to `/library` on `add-prompt`.
> - **Library/Dialogs**
> - Add controlled open state and `prefillData` support to
`CreateOrEditPromptDialog` and `CreatePromptDialog`
(`src/components/CreatePromptDialog.tsx`).
> - In `src/pages/library.tsx`, listen for `add-prompt` deep link,
prefill form, open dialog, and clear deep-link state.
> - **Schemas**
> - Define `AddPromptDataSchema`, `AddPromptPayload`, and
`AddPromptDeepLinkData` in `src/ipc/deep_link_data.ts` and include in
`DeepLinkData` union.
> - **E2E Tests**
> - Add Playwright test `e2e-tests/add_prompt_deep_link.spec.ts` and
ARIA snapshot to verify deep link opens prefilled dialog and saves
prompt.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
1ddb12306cfca195682c8a1b719f60093b858d54. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

src/main.ts

@@ -21,6 +21,8 @@ import { handleNeonOAuthReturn } from "./neon_admin/neon_return_handler";
 import {
   AddMcpServerConfigSchema,
   AddMcpServerPayload,
+  AddPromptDataSchema,
+  AddPromptPayload,
 } from "./ipc/deep_link_data";
 
 log.errorHandler.startCatching();
@@ -357,6 +359,32 @@ function handleDeepLinkReturn(url: string) {
     }
     return;
   }
+  // dyad://add-prompt?data=<base64-encoded-json>
+  if (parsed.hostname === "add-prompt") {
+    const data = parsed.searchParams.get("data");
+    if (!data) {
+      dialog.showErrorBox("Invalid URL", "Expected data parameter");
+      return;
+    }
+
+    try {
+      const decodedJson = atob(data);
+      const decoded = JSON.parse(decodedJson);
+      const parsedData = AddPromptDataSchema.parse(decoded);
+
+      mainWindow?.webContents.send("deep-link-received", {
+        type: parsed.hostname,
+        payload: parsedData as AddPromptPayload,
+      });
+    } catch (error) {
+      logger.error("Failed to parse add-prompt deep link:", error);
+      dialog.showErrorBox(
+        "Invalid Prompt Data",
+        "The deep link contains malformed data. Please check the URL and try again.",
+      );
+    }
+    return;
+  }
   dialog.showErrorBox("Invalid deep link URL", url);
 }