fix: AI Notebook CH connections need to send pw (#1792)

A user reported that they could not use the Notebooks feature due to a random clickhouse connection failure, pointing to a bad password. https://discord.com/channels/1149498480893640706/1149500035403350036/1473446917198315563

The reason it failed was because we weren't selecting the pw in `mongo` prior to using it in a direct `CH` connection. 

Before the fix, the call in `getAIMetadata` omitted the `selectPassword` argument:
`const connection = await getConnectionById(source.team.toString(), connectionId); // connection.password === undefined`

So when the ClickhouseClient was constructed immediately after:
```
const clickhouseClient = new ClickhouseClient({ host: connection.host, username: connection.username, password: connection.password,  });
```

`connection.password` was undefined, and the ClickHouse client connected with no password — hence the authentication failure.

The fix just adds `true` so the password is actually fetched from MongoDB and present in connection.password when the client is constructed.

.changeset/sour-feet-act.md

@@ -0,0 +1,5 @@
+---
+"@hyperdx/api": patch
+---
+
+fix: AI Notebook CH connections need to send pw

packages/api/src/controllers/ai.ts

@@ -78,6 +78,7 @@ export async function getAIMetadata(source: ISource) {
   const connection = await getConnectionById(
     source.team.toString(),
     connectionId,
+    true,
   );
 
   if (connection == null) {