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

apps/packages/infrastructure/src/bgbash/job.ts

@@ -0,0 +1,65 @@
+/**
+ * Background bash job — spawns a `bash -c` subprocess and tracks its life.
+ * Mirrors `apps/infrastructure/src/bgbash/job.rs`.
+ */
+import { spawn, type ChildProcess } from "node:child_process";
+import { randomUUID } from "node:crypto";
+
+/** A handle to a spawned background bash job. */
+export class BashJob {
+  readonly id: string;
+  readonly command: string;
+  private process: ChildProcess | null = null;
+  private cancelled = false;
+  private finished = false;
+
+  constructor(command: string) {
+    this.id = randomUUID();
+    this.command = command;
+  }
+
+  /** Spawn the `bash -c` child process and begin tracking it. */
+  start(): void {
+    const child = spawn("bash", ["-c", this.command], {
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+    this.process = child;
+
+    // Drain stdout/stderr so the process doesn't block on a full pipe, and
+    // mark finished when it exits.
+    child.stdout?.resume();
+    child.stderr?.resume();
+    child.on("exit", () => {
+      this.finished = true;
+    });
+    child.on("error", () => {
+      this.finished = true;
+    });
+  }
+
+  /** Cancel the job: set the cancelled flag and kill the child process. */
+  cancel(): void {
+    this.cancelled = true;
+    if (this.process && !this.finished) {
+      try {
+        this.process.kill("SIGKILL");
+      } catch {
+        /* already gone */
+      }
+    }
+  }
+
+  /** Whether the job is currently running. */
+  isRunning(): boolean {
+    if (this.cancelled || this.finished) return false;
+    if (!this.process) return false;
+    return this.process.exitCode === null && !this.finished;
+  }
+}
+
+/** Spawn a background bash job and return its handle (node-side). */
+export function spawnBashJob(command: string): BashJob {
+  const job = new BashJob(command);
+  job.start();
+  return job;
+}