`td`: follow the daemon's real log, and make bare `td` tail it
Logs could silently never appear. The client derived the log path from its own
cwd, but the daemon writes under the cwd it was *started* from, so submitting
from anywhere else tailed a file nobody writes: the job ran, the verdict came
back, and not a single line was shown. The daemon now records its log path in
the store and clients read it from there.
The other way to lose output is to delete `.td` while the pool is alive -- the
daemon holds the open fd and keeps writing into an unlinked inode, so jobs keep
working and the console stays empty forever. That is undetectable from the
outside, so warn about it explicitly and say how to recover.
Bare `td` now follows rank 0 instead of erroring, and replays the tail of the
log before following: a short job can finish in less time than this process
takes to import torch, so attaching at EOF showed an empty screen for work that
had already happened. `--logs` is gone; `td` is the command.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>