Q8: one writing run per workspace directory

Write-granted runs whose directories overlap (same folder, symlink or
junction, or nested) wait for each other, at claim time and for manual
runs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/unit/task-queue-worker.test.ts

@@ -1,5 +1,6 @@
 import { randomUUID } from "node:crypto";
 import { tmpdir } from "node:os";
+import { mkdirSync, symlinkSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect, test } from "vitest";
 import { RISK_LEVEL, TASK_PRIORITY, TASK_STATUS } from "../../src/shared/domain";
@@ -79,3 +80,74 @@ describe("task queue worker claim", () => {
     connection.close();
   });
 });
+
+describe("one writing run per workspace", () => {
+  test("a second write-granted run in the same workspace waits; read-only work proceeds", () => {
+    const connection = new DatabaseConnection(join(tmpdir(), `ac-queue-${randomUUID()}.db`));
+    const organization = new OrganizationService(connection.db);
+    let orgId = "";
+    let providerId = "";
+    const agents: string[] = [];
+    const tasks: string[] = [];
+    connection.transaction(() => {
+      orgId = organization.createOrganization({ organizationName: "Acme", employeeName: "Dana", mission: "m", goal: "g" });
+      providerId = (connection.db.prepare("select id from providers where org_id = ? and provider_key = 'openai'").get(orgId) as { id: string }).id;
+      const workspaceId = organization.createWorkspace({ orgId, name: "repo", localPath: tmpdir(), projectId: null });
+      for (const [name, writes] of [["Ana", true], ["Ben", true], ["Cy", false]] as const) {
+        const agentId = organization.createAgent({ orgId, name, role: "Engineer", department: "Engineering", modelProviderId: providerId, modelId: "gpt-5.4", budgetCents: 1000, managerAgentId: null });
+        agents.push(agentId);
+        tasks.push(organization.createTask({
+          orgId, title: `${name} work`, description: "d", status: TASK_STATUS.BACKLOG, assigneeAgentId: agentId,
+          risk: RISK_LEVEL.LOW, projectId: null, goalId: null, workspaceId, priority: TASK_PRIORITY.NORMAL, requiresFilesystem: writes,
+        }));
+      }
+    });
+    const runs = tasks.map((taskId, index) => seedQueuedRun(connection, orgId, taskId, agents[index], providerId));
+    connection.db.prepare("update task_runs set created_at = ? where id = ?").run("2026-01-01T00:00:01Z", runs[0]);
+    connection.db.prepare("update task_runs set created_at = ? where id = ?").run("2026-01-01T00:00:02Z", runs[1]);
+    connection.db.prepare("update task_runs set created_at = ? where id = ?").run("2026-01-01T00:00:03Z", runs[2]);
+
+    expect(claimNextQueuedRun(connection)?.id).toBe(runs[0]);
+    expect(claimNextQueuedRun(connection)?.id).toBe(runs[2]);
+    expect(claimNextQueuedRun(connection)).toBeNull();
+    connection.db.prepare("update task_runs set state = 'completed' where id = ?").run(runs[0]);
+    expect(claimNextQueuedRun(connection)?.id).toBe(runs[1]);
+    connection.close();
+  });
+});
+
+describe("workspace write lock follows the directory", () => {
+  test("one folder, a junction to it, and nested folders (even not yet created) share the lock", () => {
+    const connection = new DatabaseConnection(join(tmpdir(), `ac-queue-${randomUUID()}.db`));
+    const organization = new OrganizationService(connection.db);
+    const root = join(tmpdir(), `ac-repo-${randomUUID()}`);
+    mkdirSync(root, { recursive: true });
+    const linked = join(tmpdir(), `ac-link-${randomUUID()}`);
+    symlinkSync(root, linked, "junction");
+    let orgId = "";
+    let providerId = "";
+    const runs: string[] = [];
+    connection.transaction(() => {
+      orgId = organization.createOrganization({ organizationName: "Acme", employeeName: "Dana", mission: "m", goal: "g" });
+      providerId = (connection.db.prepare("select id from providers where org_id = ? and provider_key = 'openai'").get(orgId) as { id: string }).id;
+      const paths = [root, linked, `${root}/`, join(root, "packages", "api"), join(linked, "packages", "api", "src")];
+      paths.forEach((localPath, index) => {
+        const workspaceId = organization.createWorkspace({ orgId, name: `w${index}`, localPath, projectId: null });
+        const agentId = organization.createAgent({ orgId, name: `Dev${index}`, role: "Engineer", department: "Engineering", modelProviderId: providerId, modelId: "gpt-5.4", budgetCents: 1000, managerAgentId: null });
+        const taskId = organization.createTask({
+          orgId, title: `t${index}`, description: "d", status: TASK_STATUS.BACKLOG, assigneeAgentId: agentId,
+          risk: RISK_LEVEL.LOW, projectId: null, goalId: null, workspaceId, priority: TASK_PRIORITY.NORMAL, requiresFilesystem: true,
+        });
+        runs.push(seedQueuedRun(connection, orgId, taskId, agentId, providerId));
+      });
+    });
+    runs.forEach((runId, index) => connection.db.prepare("update task_runs set created_at = ? where id = ?").run(`2026-01-01T00:00:0${index}Z`, runId));
+
+    for (const runId of runs) {
+      expect(claimNextQueuedRun(connection)?.id).toBe(runId);
+      expect(claimNextQueuedRun(connection)).toBeNull();
+      connection.db.prepare("update task_runs set state = 'completed' where id = ?").run(runId);
+    }
+    connection.close();
+  });
+});