fix: use ControlPersist yes — let key auth handle its own timeout

INSTALL.md

@@ -184,12 +184,12 @@ Based on what the user chose:
    Host *
        ControlMaster auto
        ControlPath ~/.ssh/sockets/%r@%h-%p
-       ControlPersist 600
+       ControlPersist yes
    SSHEOF
    ```
 
    Explain to the user how it works:
-   > **How this works:** When you SSH into a remote machine, the connection stays open in the background for 10 minutes (`ControlPersist 600`). During that time, any other SSH command to the same host — including ones I run — reuses your authenticated tunnel. No password prompt, no key tap. Just open an SSH session to your target machine before asking me to work on it.
+   > **How this works:** When you SSH into a remote machine, the connection stays open in the background for 10 minutes (`ControlPersist yes`). During that time, any other SSH command to the same host — including ones I run — reuses your authenticated tunnel. No password prompt, no key tap. The tunnel stays open until the original session closes or the connection drops — your key/auth provider handles its own timeout. Just open an SSH session to your target machine before asking me to work on it.
 
    If the user's `~/.ssh/config` already has Host-specific blocks, add the ControlMaster settings under a `Host *` block at the **end** of the file so it acts as a default without overriding specific host configs.