feature!: параметр user_agent убран, UA всегда родной; docs/Usage.md

- user_agent в запросе → 422 с подсказкой брать UA из ответа: UA, отличный от реального
  Chrome, расходится с userAgentData и движком, Cloudflare такой браузер не пропускает
  (замер: родной 3/3, Chrome 147 и Windows — 0) (#87)
- профиль хранит только отпечаток (экран, DPR), UA не подменяется (#89)
- docs/Usage.md: практики для клиентов API — тот же UA и прокси, что у браузера, сессии,
  cookies, ошибки и повторы, таймауты, пример на httpx
- README, docs/API.md, docs/Introduction.md; тесты под новый контракт

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

tests/unit/test_profile.py

@@ -1,36 +1,24 @@
 import json
 
-import pytest
-
 from api import profile
 
 
-@pytest.fixture(autouse=True)
-def chrome_155(monkeypatch):
-	monkeypatch.setattr(profile, "chrome_major", lambda: "155")
+def test_fingerprint_generated_once(tmp_path):
+	first = profile.load_or_create(tmp_path)
+	assert profile.load_or_create(tmp_path) == first
+	assert json.loads((tmp_path / profile.SETTINGS_FILE).read_text()) == first
 
-
-def test_passed_user_agent_is_saved_once(tmp_path):
-	first = profile.load_or_create(tmp_path, "First/1")
-	second = profile.load_or_create(tmp_path, "Second/2")
-
-	assert first == second == {"user_agent": "First/1"}
-	assert json.loads((tmp_path / profile.SETTINGS_FILE).read_text()) == {"user_agent": "First/1"}
-
-
-def test_generated_fingerprint_without_user_agent(tmp_path):
-	settings = profile.load_or_create(tmp_path, None)
-
-	assert settings["user_agent"] == profile.UA_TEMPLATE.format(major="155")
-	screen = settings["fingerprint"]["screen"]
+	screen = first["fingerprint"]["screen"]
 	assert screen["width"] >= profile.MIN_SCREEN[0] and screen["height"] >= profile.MIN_SCREEN[1]
-	assert settings["fingerprint"]["device_scale_factor"] >= 1
+	assert first["fingerprint"]["device_scale_factor"] >= 1
+	assert "user_agent" not in first
 
 
-def test_generated_fingerprint_is_stable_and_ignores_later_user_agent(tmp_path):
-	first = profile.load_or_create(tmp_path, None)
-	assert profile.load_or_create(tmp_path, None) == first
-	assert profile.load_or_create(tmp_path, "Later/1") == first
+def test_old_profile_settings_get_fingerprint(tmp_path):
+	"""Профиль из версии, где сохранялся user_agent клиента: UA отбрасывается, отпечаток создаётся."""
+	(tmp_path / profile.SETTINGS_FILE).write_text(json.dumps({"user_agent": "First/1"}))
+	settings = profile.load_or_create(tmp_path)
+	assert set(settings) == {"fingerprint"}
 
 
 def test_profiles_get_independent_fingerprints(tmp_path):
@@ -39,7 +27,7 @@ def test_profiles_get_independent_fingerprints(tmp_path):
 	for i in range(30):
 		d = tmp_path / str(i)
 		d.mkdir()
-		fp = profile.load_or_create(d, None)["fingerprint"]
+		fp = profile.load_or_create(d)["fingerprint"]
 		variants.add((fp["screen"]["width"], fp["screen"]["height"], fp["device_scale_factor"]))
 	assert len(variants) > 1
 
@@ -50,18 +38,9 @@ def test_generate_falls_back_when_browserforge_fails(monkeypatch):
 			raise ValueError("Cannot generate headers")
 
 	monkeypatch.setattr(profile, "FingerprintGenerator", Failing)
-	fp = profile.generate_fingerprint(attempts=2)
-	assert fp["screen"] == {"width": 1920, "height": 1080}
-	assert fp["device_scale_factor"] == 1
+	assert profile.generate_fingerprint(attempts=2) == {"screen": {"width": 1920, "height": 1080}, "device_scale_factor": 1}
 
 
-def test_browser_kwargs():
-	assert profile.browser_kwargs({"user_agent": "UA/1"}) == {"useragent": "UA/1"}
-	kwargs = profile.browser_kwargs({
-		"user_agent": "UA/1",
-		"fingerprint": {"screen": {"width": 2560, "height": 1440}, "device_scale_factor": 1.25},
-	})
-	assert kwargs == {
-		"useragent": "UA/1",
-		"additional_args": {"screen": {"width": 2560, "height": 1440}, "device_scale_factor": 1.25},
-	}
+def test_browser_kwargs_do_not_touch_user_agent():
+	kwargs = profile.browser_kwargs({"fingerprint": {"screen": {"width": 2560, "height": 1440}, "device_scale_factor": 1.25}})
+	assert kwargs == {"additional_args": {"screen": {"width": 2560, "height": 1440}, "device_scale_factor": 1.25}}

tests/unit/test_schemas.py

@@ -68,6 +68,11 @@ def test_proxy_optional():
 	assert solve(proxy="").proxy is None
 
 
+def test_user_agent_rejected():
+	with pytest.raises(ValidationError, match="user_agent is not supported"):
+		solve(user_agent="Mozilla/5.0")
+
+
 def test_captcha_action_requires_key():
 	action = {"type": "captcha", "selector": "#c", "value": "recaptcha"}
 	with pytest.raises(ValidationError, match="requires request field 'captcha'"):

tests/unit/test_solve.py

@@ -54,7 +54,6 @@ def client(monkeypatch, tmp_path):
 	monkeypatch.setattr(main, "AsyncStealthySession", FakeSession)
 	monkeypatch.setattr(main, "USER_DATA_ROOT", tmp_path)
 	monkeypatch.setattr(main, "_slots", asyncio.Semaphore(2))
-	monkeypatch.setattr(profile, "chrome_major", lambda: "155")
 	return TestClient(main.app)
 
 
@@ -168,18 +167,18 @@ def test_bad_session_cookie_gets_new_session(client, monkeypatch, tmp_path, bad)
 	assert [p.name for p in tmp_path.iterdir()] == [sid]
 
 
-def test_user_agent_set_once_per_profile(client, monkeypatch):
-	monkeypatch.setattr(actions, "execute", fake_execute([]))
-	post(client, user_agent="First/1")
-	post(client, user_agent="Second/2")
-	assert [c["useragent"] for c in FakeSession.calls] == ["First/1", "First/1"]
+def test_user_agent_param_rejected(client):
+	resp = post(client, user_agent="First/1")
+	assert resp.status_code == 422
+	assert "take user_agent from the response" in resp.text
+	assert FakeSession.calls == []
 
 
-def test_generated_fingerprint_passed_to_browser(client, monkeypatch):
+def test_fingerprint_passed_to_browser_and_ua_untouched(client, monkeypatch):
 	monkeypatch.setattr(actions, "execute", fake_execute([]))
 	post(client)
 	kwargs = FakeSession.calls[0]
-	assert kwargs["useragent"] == profile.UA_TEMPLATE.format(major="155")
+	assert "useragent" not in kwargs
 	assert set(kwargs["additional_args"]) == {"screen", "device_scale_factor"}