chore: rework tools execution workflow (#5278)

Re-work the tool execution flow. Read `orchestrator.rs` to understand
the structure

codex-rs/Cargo.lock

@@ -1056,6 +1056,7 @@ dependencies = [
  "codex-otel",
  "codex-protocol",
  "codex-rmcp-client",
+ "codex-utils-pty",
  "codex-utils-string",
  "core-foundation 0.9.4",
  "core_test_support",
@@ -1072,7 +1073,6 @@ dependencies = [
  "mcp-types",
  "openssl-sys",
  "os_info",
- "portable-pty",
  "predicates",
  "pretty_assertions",
  "rand 0.9.2",
@@ -1484,6 +1484,15 @@ dependencies = [
  "toml",
 ]
 
+[[package]]
+name = "codex-utils-pty"
+version = "0.0.0"
+dependencies = [
+ "anyhow",
+ "portable-pty",
+ "tokio",
+]
+
 [[package]]
 name = "codex-utils-readiness"
 version = "0.0.0"