Process.stop() lacks SIGKILL fallback — LSP processes become zombies

[beowulfof]

Summary

Process.stop() in packages/opencode/src/util/process.ts sends only proc.kill() (SIGTERM) with no timeout and no SIGKILL escalation. If an LSP server ignores SIGTERM (e.g. rust-analyzer, clangd, Java-based servers), the process remains as a zombie.

Root Cause

The abort handler in Process.spawn() (same file) already has the correct pattern: SIGTERM → 5s timeout → SIGKILL. But stop() was written as a simple synchronous proc.kill() without any follow-up.

Impact

• Orphaned LSP processes accumulate, consuming memory and file descriptors
• Instance disposal hangs if a server doesn't respond to SIGTERM
• The process.exit() fallback in index.ts only cleans up on main-process exit, not during normal operation

Steps to Reproduce

1. Use an LSP server that ignores SIGTERM (e.g. some configurations of rust-analyzer or clangd)
2. Close the project or instance
3. The LSP process remains running

Related

• LSP processes remain as orphaned zombie processes after opencode exits, causing severe memory leaks #18632 (LSP orphan processes)
• LSP process leak: rust-analyzer spawned repeatedly without shutdown, causes OOM #17287 (LSP process leak)