feature: действие captcha value=image — капча-картинка через 2captcha (#109)

Снимок элемента картинки на текущей странице (без повторной загрузки src) уходит
в 2captcha как обычная капча (method=base64), ответ набирается в поле target
как у typing и возвращается в result действия. Необязательные подсказки:
min_len, max_len, numeric, lang, case_sensitive. Клиент: Action.captcha_image.

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

tests/unit/test_schemas.py

@@ -21,6 +21,13 @@ def solve(**kwargs) -> SolveRequest:
 	({"type": "wait_for", "selector": "a", "timeout": 0}, "between 1 and 7200"),
 	({"type": "wait_for", "selector": "a", "timeout": 7201}, "between 1 and 7200"),
 	({"type": "captcha", "selector": "#c", "value": "datadome"}, "captcha value must be one of"),
+	({"type": "captcha", "selector": "img", "value": "image"}, "requires: target"),
+	({"type": "captcha", "selector": "#c", "value": "hcaptcha", "target": "#in"}, "only for action 'captcha'"),
+	({"type": "typing", "selector": "#q", "value": "x", "numeric": 1}, "only for action 'captcha'"),
+	({"type": "captcha", "selector": "img", "value": "image", "target": "#in", "numeric": 5}, "numeric"),
+	({"type": "captcha", "selector": "img", "value": "image", "target": "#in", "max_len": 21}, "max_len"),
+	({"type": "captcha", "selector": "img", "value": "image", "target": "#in", "min_len": 6, "max_len": 4},
+		"min_len must not exceed max_len"),
 ])
 def test_invalid_action(action, error):
 	with pytest.raises(ValidationError, match=error):
@@ -35,6 +42,9 @@ def test_invalid_action(action, error):
 	{"type": "delay", "value": "0"},
 	{"type": "pass_challenge"},
 	{"type": "captcha", "selector": "#c", "value": "hcaptcha"},
+	{"type": "captcha", "selector": "img", "value": "image", "target": "#in"},
+	{"type": "captcha", "selector": "img", "value": "image", "target": "#in",
+		"min_len": 4, "max_len": 6, "numeric": 1, "lang": "en", "case_sensitive": True},
 	{"type": "inner_html", "selector": "h1"},
 ])
 def test_valid_action(action):