fix: use STATE_DIR instead of hardcoded ~/.openclaw for identity and canvas (#4824)

* fix: use STATE_DIR instead of hardcoded ~/.openclaw for identity and canvas

device-identity.ts and canvas-host/server.ts used hardcoded
path.join(os.homedir(), '.openclaw', ...) ignoring OPENCLAW_STATE_DIR
env var and the resolveStateDir() logic from config/paths.ts.

This caused ~/.openclaw/identity and ~/.openclaw/canvas directories
to be created even when state dir was overridden or resided elsewhere.

* fix: format and remove duplicate imports

* fix: scope state-dir patch + add regression tests (#4824) (thanks @kossoy)

* fix: align state-dir fallbacks in hooks and agent paths (#4824) (thanks @kossoy)

---------

Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/infra/device-identity.state-dir.test.ts

@@ -0,0 +1,40 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  restoreStateDirEnv,
+  setStateDirEnv,
+  snapshotStateDirEnv,
+} from "../test-helpers/state-dir-env.js";
+
+describe("device identity state dir defaults", () => {
+  let envSnapshot: ReturnType<typeof snapshotStateDirEnv>;
+
+  beforeEach(() => {
+    envSnapshot = snapshotStateDirEnv();
+  });
+
+  afterEach(() => {
+    vi.resetModules();
+    restoreStateDirEnv(envSnapshot);
+  });
+
+  it("writes the default identity file under OPENCLAW_STATE_DIR", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-identity-state-"));
+    const stateDir = path.join(tempRoot, "state");
+    setStateDirEnv(stateDir);
+    vi.resetModules();
+
+    const { loadOrCreateDeviceIdentity } = await import("./device-identity.js");
+    const identity = loadOrCreateDeviceIdentity();
+
+    try {
+      const identityPath = path.join(stateDir, "identity", "device.json");
+      const raw = JSON.parse(await fs.readFile(identityPath, "utf8")) as { deviceId?: string };
+      expect(raw.deviceId).toBe(identity.deviceId);
+    } finally {
+      await fs.rm(tempRoot, { recursive: true, force: true });
+    }
+  });
+});