feat: assistant role (#1588)

Introduces the ability for users with the **Assistant** role to prefill
fields on behalf of other signers. Assistants can fill in various field
types such as text, checkboxes, dates, and more, streamlining the
document preparation process before it reaches the final signers.

apps/remix/app/components/general/document-signing/document-signing-recipient-provider.tsx

@@ -0,0 +1,67 @@
+import { type PropsWithChildren, createContext, useContext } from 'react';
+
+import type { Recipient } from '@prisma/client';
+
+import type { RecipientWithFields } from '@documenso/prisma/types/recipient-with-fields';
+
+export interface DocumentSigningRecipientContextValue {
+  /**
+   * The recipient who is currently signing the document.
+   * In regular mode, this is the actual signer.
+   * In assistant mode, this is the recipient who is helping fill out the document.
+   */
+  recipient: Recipient | RecipientWithFields;
+
+  /**
+   * Only present in assistant mode.
+   * The recipient on whose behalf we're filling out the document.
+   */
+  targetSigner: RecipientWithFields | null;
+
+  /**
+   * Whether we're in assistant mode (one recipient filling out for another)
+   */
+  isAssistantMode: boolean;
+}
+
+const DocumentSigningRecipientContext = createContext<DocumentSigningRecipientContextValue | null>(
+  null,
+);
+
+export interface DocumentSigningRecipientProviderProps extends PropsWithChildren {
+  recipient: Recipient | RecipientWithFields;
+  targetSigner?: RecipientWithFields | null;
+}
+
+export const DocumentSigningRecipientProvider = ({
+  children,
+  recipient,
+  targetSigner = null,
+}: DocumentSigningRecipientProviderProps) => {
+  // console.log({
+  //   recipient,
+  //   targetSigner,
+  //   isAssistantMode: !!targetSigner,
+  // });
+  return (
+    <DocumentSigningRecipientContext.Provider
+      value={{
+        recipient,
+        targetSigner,
+        isAssistantMode: !!targetSigner,
+      }}
+    >
+      {children}
+    </DocumentSigningRecipientContext.Provider>
+  );
+};
+
+export function useDocumentSigningRecipientContext() {
+  const context = useContext(DocumentSigningRecipientContext);
+
+  if (!context) {
+    throw new Error('useDocumentSigningRecipientContext must be used within a RecipientProvider');
+  }
+
+  return context;
+}