fix: clean up MCP subprocesses after abrupt parent exit (#8242)

Signed-off-by: fre <anonwurcod@proton.me>
Signed-off-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Oz <oz-agent@warp.dev>
Co-authored-by: Douwe Osinga <douwe@squareup.com>

Cargo.lock

@@ -4369,6 +4369,7 @@ dependencies = [
  "jsonwebtoken",
  "keyring",
  "lazy_static",
+ "libc",
  "llama-cpp-2",
  "lru",
  "minijinja",
@@ -5746,9 +5747,9 @@ checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"
 
 [[package]]
 name = "libc"
-version = "0.2.183"
+version = "0.2.184"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
+checksum = "48f5d2a454e16a5ea0f4ced81bd44e4cfc7bd3a507b61887c99fd3538b28e4af"
 
 [[package]]
 name = "libdbus-sys"