fix(compose): retain an explicit zero log tail (#673)

Compose service logs now pass --tail only for finite values, so an explicit zero reaches Compose as --tail 0, while undefined and NaN omit the flag as before.

packages/daemon/src/adapters/compose-services-adapter.ts

@@ -130,7 +130,7 @@ export class ComposeServicesAdapter {
   }): Promise<ComposeLogsResult> {
     const args = this.baseArgs(opts.composeFile, opts.projectName, opts.profiles);
     const serviceArg = opts.service ? ` ${sq(opts.service)}` : "";
-    const tailArg = opts.tail ? ` --tail ${opts.tail}` : "";
+    const tailArg = Number.isFinite(opts.tail) ? ` --tail ${opts.tail}` : "";
     const cmd = `docker compose ${args} logs${tailArg}${serviceArg} 2>&1`;
     try {
       const output = await this.exec(cmd);

packages/daemon/test/compose-zero-tail-native.test.ts

@@ -0,0 +1,41 @@
+import { afterEach, expect, it } from "vitest";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+import { ComposeServicesAdapter } from "../src/adapters/compose-services-adapter.js";
+
+const execute = promisify(execFile);
+const dirs: string[] = [];
+afterEach(() => {
+  for (const dir of dirs.splice(0)) {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+it.skipIf(process.platform === "win32").each([0, 25, undefined, NaN])("preserves explicit zero log tail in native argument dispatch: %s", async (tail) => {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "compose-tail-argv-"));
+  dirs.push(dir);
+  // Controlled executable records real shell arguments; it never contacts Docker.
+  fs.writeFileSync(path.join(dir, "docker"), '#!/bin/sh\nprintf "%s\\n" "$@"\n', { mode: 0o700 });
+  const adapter = new ComposeServicesAdapter(async (command) => {
+    const { stdout } = await execute("/bin/sh", ["-c", command], { env: { PATH: dir } });
+    return stdout;
+  });
+  const result = await adapter.logs({
+    composeFile: path.join(dir, "services.yaml"),
+    projectName: "owned-fixture",
+    service: "api",
+    tail,
+  });
+  expect(result.ok).toBe(true);
+  const args = result.output.trim().split("\n");
+  if (tail === undefined || Number.isNaN(tail)) {
+    expect(args).not.toContain("--tail");
+  } else {
+    const tailIndex = args.indexOf("--tail");
+    expect(args.slice(tailIndex, tailIndex + 2)).toEqual(["--tail", String(tail)]);
+  }
+  expect(args.at(-1)).toBe("api");
+});