feat(ipc): port 3g IPC + bgbash — framed Unix-socket server/client + background job registry, wire bash tools

apps/packages/infrastructure/src/ipc/server.ts

@@ -0,0 +1,60 @@
+/**
+ * IPC server — binds a Unix socket and accepts incoming client connections.
+ * Mirrors `apps/infrastructure/src/ipc/server.rs`.
+ */
+import * as net from "node:net";
+import * as fs from "node:fs";
+import { Connection } from "./conn.ts";
+
+/** A Unix-socket IPC server. */
+export class IpcServer {
+  private server: net.Server;
+  private path: string;
+
+  private constructor(path: string, server: net.Server) {
+    this.path = path;
+    this.server = server;
+  }
+
+  /** Bind a Unix-socket server at `path`, removing any stale socket file. */
+  static bindUnix(path: string): Promise<IpcServer> {
+    return new Promise((resolve, reject) => {
+      if (fs.existsSync(path)) {
+        fs.unlinkSync(path);
+      }
+      const server = net.createServer();
+      server.once("error", reject);
+      server.listen(path, () => {
+        resolve(new IpcServer(path, server));
+      });
+    });
+  }
+
+  /** Accept the next incoming connection as a `Connection`. */
+  accept(): Promise<Connection> {
+    return new Promise((resolve) => {
+      const onConnection = (socket: net.Socket) => {
+        serverCleanup();
+        resolve(new Connection(socket));
+      };
+      const serverCleanup = () => {
+        this.server.removeListener("connection", onConnection);
+      };
+      this.server.once("connection", onConnection);
+    });
+  }
+
+  /** Close the server and remove the socket file. */
+  close(): Promise<void> {
+    return new Promise((resolve) => {
+      this.server.close(() => {
+        try {
+          fs.unlinkSync(this.path);
+        } catch {
+          /* ignore */
+        }
+        resolve();
+      });
+    });
+  }
+}