feat: US-071 - Add bounded IPC channels with backpressure

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: NathanFlurry

crates/v8-runtime/src/main.rs

@@ -376,7 +376,7 @@ fn main() {
                     let writer_stream = stream.try_clone().expect("failed to clone UDS stream");
                     set_cloexec(writer_stream.as_raw_fd())
                         .expect("failed to set CLOEXEC on cloned stream");
-                    let (ipc_tx, ipc_rx) = crossbeam_channel::unbounded::<Vec<u8>>();
+                    let (ipc_tx, ipc_rx) = crossbeam_channel::bounded::<Vec<u8>>(1024);
                     let call_id_router: CallIdRouter = Arc::new(Mutex::new(HashMap::new()));
 
                     // Spawn dedicated writer thread — only this thread writes to the socket

crates/v8-runtime/src/session.rs

@@ -90,7 +90,7 @@ impl SessionManager {
             return Err(format!("session {} already exists", session_id));
         }
 
-        let (tx, rx) = crossbeam_channel::unbounded();
+        let (tx, rx) = crossbeam_channel::bounded(256);
         let slot_control = Arc::clone(&self.slot_control);
         let max = self.max_concurrency;
         let ipc_tx = self.ipc_tx.clone();