Previously we were configuring using the display name of the user, which
may contain spaces, special characters, and isn't unique. This was
always supposed to be the username.
Migrates us to `coder/websocket` v1.8.12 rather than `nhooyr/websocket` on an older version.
Works around https://github.com/coder/websocket/issues/504 by adding an explicit test for `xerrors.Is(err, io.EOF)` where we were previously getting `io.EOF` from the netConn.
Closes#14734.
- Each outgoing agent upsertion also includes the timestamp of the last wireguard handshake.
- Agent upsertions will be created, for existing agents, with an updated last handshake time on a regular, fixed, interval of 10 seconds.
Addresses #14734.
This PR wires up `tunnel.go` to a `tailnet.Conn` via the new `/tailnet` endpoint, with all the necessary controllers such that a VPN connection can be started, stopped and inspected via the CoderVPN protocol.
Ethan