Fix IPC on Forge 1.17.1 - 1.20.1 (#4187)

* Reapply "Implement a more robust IPC system between the launcher and client (#4159)"

This reverts commit e25d726da4.

* Put game JAR and theseus JAR ahead of other JARs in classpath

* Fix 1.17-1.20 Forge by forcefully removing Multi-Release manifest entry

* Fix formatting

---------

Co-authored-by: Prospector <6166773+Prospector@users.noreply.github.com>

packages/app-lib/src/state/process.rs

@@ -2,6 +2,7 @@ use crate::event::emit::{emit_process, emit_profile};
 use crate::event::{ProcessPayloadType, ProfilePayloadType};
 use crate::profile;
 use crate::util::io::IOError;
+use crate::util::rpc::RpcServer;
 use chrono::{DateTime, NaiveDateTime, TimeZone, Utc};
 use dashmap::DashMap;
 use quick_xml::Reader;
@@ -15,7 +16,7 @@ use std::path::{Path, PathBuf};
 use std::process::ExitStatus;
 use tempfile::TempDir;
 use tokio::io::{AsyncBufReadExt, BufReader};
-use tokio::process::{Child, ChildStdin, Command};
+use tokio::process::{Child, Command};
 use uuid::Uuid;
 
 const LAUNCHER_LOG_PATH: &str = "launcher_log.txt";
@@ -46,9 +47,10 @@ impl ProcessManager {
         logs_folder: PathBuf,
         xml_logging: bool,
         main_class_keep_alive: TempDir,
+        rpc_server: RpcServer,
         post_process_init: impl AsyncFnOnce(
             &ProcessMetadata,
-            &mut ChildStdin,
+            &RpcServer,
         ) -> crate::Result<()>,
     ) -> crate::Result<ProcessMetadata> {
         mc_command.stdout(std::process::Stdio::piped());
@@ -67,14 +69,12 @@ impl ProcessManager {
                 profile_path: profile_path.to_string(),
             },
             child: mc_proc,
+            rpc_server,
             _main_class_keep_alive: main_class_keep_alive,
         };
 
-        if let Err(e) = post_process_init(
-            &process.metadata,
-            &mut process.child.stdin.as_mut().unwrap(),
-        )
-        .await
+        if let Err(e) =
+            post_process_init(&process.metadata, &process.rpc_server).await
         {
             tracing::error!("Failed to run post-process init: {e}");
             let _ = process.child.kill().await;
@@ -165,6 +165,10 @@ impl ProcessManager {
         self.processes.get(&id).map(|x| x.metadata.clone())
     }
 
+    pub fn get_rpc(&self, id: Uuid) -> Option<RpcServer> {
+        self.processes.get(&id).map(|x| x.rpc_server.clone())
+    }
+
     pub fn get_all(&self) -> Vec<ProcessMetadata> {
         self.processes
             .iter()
@@ -215,6 +219,7 @@ struct Process {
     metadata: ProcessMetadata,
     child: Child,
     _main_class_keep_alive: TempDir,
+    rpc_server: RpcServer,
 }
 
 #[derive(Debug, Default)]