refactor(test): dedupe agent harnesses and routing fixtures

src/agents/bash-process-registry.test-helpers.ts

@@ -0,0 +1,42 @@
+import type { ChildProcessWithoutNullStreams } from "node:child_process";
+import type { ProcessSession } from "./bash-process-registry.js";
+
+export function createProcessSessionFixture(params: {
+  id: string;
+  command?: string;
+  startedAt?: number;
+  cwd?: string;
+  maxOutputChars?: number;
+  pendingMaxOutputChars?: number;
+  backgrounded?: boolean;
+  pid?: number;
+  child?: ChildProcessWithoutNullStreams;
+}): ProcessSession {
+  const session: ProcessSession = {
+    id: params.id,
+    command: params.command ?? "test",
+    startedAt: params.startedAt ?? Date.now(),
+    cwd: params.cwd ?? "/tmp",
+    maxOutputChars: params.maxOutputChars ?? 10_000,
+    pendingMaxOutputChars: params.pendingMaxOutputChars ?? 30_000,
+    totalOutputChars: 0,
+    pendingStdout: [],
+    pendingStderr: [],
+    pendingStdoutChars: 0,
+    pendingStderrChars: 0,
+    aggregated: "",
+    tail: "",
+    exited: false,
+    exitCode: undefined,
+    exitSignal: undefined,
+    truncated: false,
+    backgrounded: params.backgrounded ?? false,
+  };
+  if (params.pid !== undefined) {
+    session.pid = params.pid;
+  }
+  if (params.child) {
+    session.child = params.child;
+  }
+  return session;
+}