Add normalizer to strip <reminder> tags from user messages

The CLI now injects dynamic <reminder> tags with SQL table state into user
messages. These tags vary based on runtime state and should not affect
snapshot matching.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SteveSandersonMS

test/harness/replayingCapiProxy.ts

@@ -631,6 +631,7 @@ function transformOpenAIRequestMessage(
 function normalizeUserMessage(content: string): string {
   return content
     .replace(/<current_datetime>.*?<\/current_datetime>/g, "")
+    .replace(/<reminder>[\s\S]*?<\/reminder>/g, "")
     .trim();
 }