Terminal creation no longer waits for the Ghostty viewport to report its
size: it starts the PTY immediately with a container/font-derived
provisional size (falling back to 80x24), then resizes once the real
viewport dimensions are known, with a dedupe guard while sizing settles.
Starting the shell earlier means it can emit device/theme queries before
a browser terminal is attached to answer them, so the server now answers
primary device attribute queries itself (Fish blocks ~10s on this at
startup) and bun-pty buffers output emitted before a data subscriber
attaches. Also fixes a few WebSocket transport reconnect races surfaced
by session creation now overlapping renderer setup.
Serhii Dziupin