feat: support concurrent Reddit accounts

apps/dashboard/src/features/conversations/start-conversation-form.tsx

@@ -1,6 +1,8 @@
 import { useState } from 'react';
 import { RedditUsernameLink } from '../../components/reddit-username-link.js';
 import { useStartConversationMutation } from './conversation-queries.js';
+import { useRedditAccountsQuery } from '../settings/settings-queries.js';
+import { ownedConversationId } from './conversation-identity.js';
 
 interface StartConversationFormProps {
   onStarted(conversationId: string): void;
@@ -9,21 +11,25 @@ interface StartConversationFormProps {
 export function StartConversationForm({ onStarted }: StartConversationFormProps) {
   const [username, setUsername] = useState('');
   const [message, setMessage] = useState('');
+  const accountsQuery = useRedditAccountsQuery();
+  const runningAccounts = (accountsQuery.data ?? []).filter((account) => account.isRunning);
+  const [selectedAccountId, setSelectedAccountId] = useState('');
+  const accountId = selectedAccountId || runningAccounts[0]?.accountId || '';
   const [successUsername, setSuccessUsername] = useState<string | null>(null);
   const mutation = useStartConversationMutation();
-  const canSubmit = username.trim().length > 0 && message.trim().length > 0 && !mutation.isPending;
+  const canSubmit = accountId.length > 0 && username.trim().length > 0 && message.trim().length > 0 && !mutation.isPending;
 
   function submit(event: React.FormEvent<HTMLFormElement>) {
     event.preventDefault();
     if (!canSubmit) return;
     mutation.mutate(
-      { username, message },
+      { accountId, username, message },
       {
         onSuccess(chat) {
           setSuccessUsername(chat.username);
           setUsername('');
           setMessage('');
-          onStarted(chat.roomId ?? chat.username);
+          onStarted(ownedConversationId(chat));
         },
       },
     );
@@ -31,6 +37,12 @@ export function StartConversationForm({ onStarted }: StartConversationFormProps)
 
   return (
     <form className="start-conversation-form" onSubmit={submit}>
+      <div className="conversation-field">
+        <label htmlFor="new-conversation-account">Send from account</label>
+        <select id="new-conversation-account" onChange={(event) => setSelectedAccountId(event.target.value)} value={accountId}>
+          {runningAccounts.map((account) => <option key={account.accountId} value={account.accountId}>u/{account.redditUsername}</option>)}
+        </select>
+      </div>
       <div className="conversation-field">
         <label htmlFor="new-conversation-username">Reddit username</label>
         <input