You cannot combine the summary of chats with that workaround, no, but you could make a /log command which instructs the agent to summarise the chat and save it as an entry into a log.md file.
You could then @-mention your new conversation or write a Project Rule that tells the agent to read it when starting a new chat.
The Git commits were also removed due to reliability issues.
Also, the Agent can reliably gather this information when needed on its own, so you should simply be able to ask the agent to read your last commit, or analyze the diff between your current branch and main.
Also, if you find you are doing this a lot, you can make a command called something like /pr, which would act as shorthand for the instructions you want to give the agent.