Previously, any LSP server failure during initialize (process crash, missing
binary, rustup proxy error) was reported as a generic "timed out" message.
The process exit and its stderr were ignored; only the per-request timeout
fired, hiding the actual cause.
proc.exited now rejects all pending requests with the server's stderr output.
ptree already captures stderr and awaits its completion for non-zero exits,
so peekStderr() is reliable at this point. The first rejection wins the race
against the timeout; the other finds the request already removed and no-ops.
Also added warmupTimeoutMs to ServerConfig, allowing per-server override of
the global 5s warmup cap via lsp.json/lsp.yaml. Servers without it fall back
to WARMUP_TIMEOUT_MS as before.
Timeout error messages now include the configured duration for clarity when
they do legitimately fire.
Yigit Colakoglu
c52223ad5c