[OMEGA-490] Remove legacy antispam filter, fix dropped token limit notifications - #383

--- a/providers/lib_llm_ext.py
+++ b/providers/lib_llm_ext.py
@@ -4,3 +4,3 @@ from typing import Optional, Tuple, Dict, Any
 from config import config_get_by_key
-from src.helper import quote_arg
+from src.helper import quote_arg, split_command_blocks
 from src.logger import get_logger
@@ -69,2 +69,26 @@ def _llm_empty_response_command() -> str:
 
+_limit_notice_pending = False
+
+def _sends_to_user(raw: str) -> bool:
+    text = raw.replace("_quote_", '"').replace("_newline_", "\n")
+    for block in split_command_blocks(text):
+        command = block.lstrip().lstrip("(").split(maxsplit=1)
+        if command and command[0].rstrip(")") == "send":
+            return True
+    return False
+
+def _reply_or_limit_notice(content: str, raw: str, cut_by_limit: bool) -> str:
+    global _limit_notice_pending
+    _, usermsg = _split_system_user(content)
+    if "HUMAN-MSG:" in usermsg:
+        _limit_notice_pending = True
+    if raw:
+        if _sends_to_user(raw):
+            _limit_notice_pending = False
+        return raw
+    if cut_by_limit and _limit_notice_pending:
+        _limit_notice_pending = False
+        return _llm_empty_response_command()
+    return raw
+
 def _split_system_user(content: str) -> Tuple[str, str]:
@@ -190,4 +214,3 @@ class AIProvider(AbstractAIProvider):
                 logger.warning("LLM returned an empty response")
-                if finish_reason == "length":
-                    raw = _llm_empty_response_command()
+            raw = _reply_or_limit_notice(content, raw, finish_reason == "length")
             resp = self._clean_text(raw)
--- a/providers/asione.py
+++ b/providers/asione.py
@@ -77,4 +77,3 @@ class ASIOneProviderImpl(llm.AIProvider):
                 logger.warning("LLM returned an empty response")
-                if finish_reason == "length":
-                    raw = llm._llm_empty_response_command()
+            raw = llm._reply_or_limit_notice(content, raw, finish_reason == "length")
             resp = self._clean_text(raw)
--- a/providers/openai.py
+++ b/providers/openai.py
@@ -64,4 +64,3 @@ class OpenAIProviderImpl(llm.AIProvider):
                 logger.warning("LLM returned an empty response")
-                if incomplete_reason == "max_output_tokens":
-                    raw = llm._llm_empty_response_command()
+            raw = llm._reply_or_limit_notice(content, raw, incomplete_reason == "max_output_tokens")
             return self._clean_text(raw)
--- a/Autotests/unit/test_llm_budget.py
+++ b/Autotests/unit/test_llm_budget.py
@@ -57,3 +57,9 @@ asione = _MODULES["asione"]
 
-PROMPT = "You are an agent. :-:-:-: Write an empty line to /tmp/paths.txt"
+PROMPT = "You are an agent. :-:-:-: (HUMAN-MSG: Write an empty line to /tmp/paths.txt)"
+IDLE_PROMPT = "You are an agent. :-:-:-: "
+
+
+@pytest.fixture(autouse=True)
+def no_pending_limit_notice():
+    llm._limit_notice_pending = False
 
@@ -158,2 +164,41 @@ def test_asione_empty_reply_out_of_budget_is_explained():
 
+@pytest.mark.parametrize("make, response", [
+    (make_openrouter, lambda: chat_response("", "length")),
+    (make_asione, lambda: chat_response("", "length")),
+    (make_openai, lambda: responses_response("", "incomplete", "max_output_tokens")),
+])
+@pytest.mark.parametrize("prompt", [IDLE_PROMPT, "You are an agent. :-:-:-:  DO NOT RE-SEND OR SPAM!"])
+def test_empty_reply_out_of_budget_without_a_user_message_sends_nothing(make, response, prompt):
+    assert make(FakeCreate(response())).chat(prompt) == ""
+
+
+def test_limit_notice_comes_once_after_a_step_without_an_answer():
+    provider = make_openrouter(FakeCreate(
+        chat_response('(query "hash maps")', "length"),
+        chat_response("", "length"),
+        chat_response("", "length"),
+    ))
+    assert provider.chat(PROMPT) == '(query "hash maps")'
+    assert sent_text(provider.chat(IDLE_PROMPT)) == llm.LLM_EMPTY_RESPONSE_MESSAGE
+    assert provider.chat(IDLE_PROMPT) == ""
+
+
+@pytest.mark.parametrize("answer", ['(send "hi")', 'send "hi"', 'Sure.\nsend "hi"', '(query "x")\n(send "hi")'])
+def test_limit_notice_is_skipped_once_the_user_got_an_answer(answer):
+    provider = make_openrouter(FakeCreate(
+        chat_response(answer, "stop"),
+        chat_response("", "length"),
+    ))
+    assert provider.chat(PROMPT) == answer
+    assert provider.chat(IDLE_PROMPT) == ""
+
+
+def test_every_user_message_cut_by_the_limit_gets_its_own_notice():
+    provider = make_openrouter(FakeCreate(*(chat_response("", "length") for _ in range(4))))
+    assert sent_text(provider.chat(PROMPT)) == llm.LLM_EMPTY_RESPONSE_MESSAGE
+    assert provider.chat(IDLE_PROMPT) == ""
+    assert sent_text(provider.chat(PROMPT)) == llm.LLM_EMPTY_RESPONSE_MESSAGE
+    assert provider.chat(IDLE_PROMPT) == ""
+
+
 @pytest.mark.parametrize("effort, max_tokens, want_budget, want_enabled", [