fix(context): preserve missing-key compression history

tests/agent/test_context_compressor.py

@@ -854,11 +854,19 @@ class TestAuthFailureAborts:
     def test_quota_classifier_accepts_explicit_provider_signals(self, message):
         assert _is_summary_access_or_quota_error(Exception(message)) is True
 
+    def test_missing_provider_api_key_is_terminal_access_failure(self):
+        err = RuntimeError(
+            "Provider 'opencode-zen' is set in config.yaml but no API key was "
+            "found. Set the OPENCODE-ZEN_API_KEY environment variable."
+        )
+        assert _is_summary_access_or_quota_error(err) is True
+
     @pytest.mark.parametrize(
         "message",
         [
             "billing portal is temporarily unavailable",
             "usage limit documentation could not be loaded",
+            "API key documentation was not found",
             "rate limit exceeded; retry later",
             "quota exceeded, please retry after the window resets",
             "request timed out",
@@ -905,6 +913,34 @@ class TestAuthFailureAborts:
         assert c._last_compress_aborted is True
         assert c._last_summary_fallback_used is False
 
+    def test_missing_provider_api_key_preserves_original_messages(self):
+        """A configured auxiliary provider without a visible key preserves context."""
+        err = RuntimeError(
+            "Provider 'opencode-zen' is set in config.yaml but no API key was "
+            "found. Set the OPENCODE-ZEN_API_KEY environment variable, or switch "
+            "to a different provider with hermes model."
+        )
+        with patch(
+            "agent.context_compressor.get_model_context_length", return_value=100000
+        ):
+            c = ContextCompressor(
+                model="test",
+                quiet_mode=True,
+                protect_first_n=2,
+                protect_last_n=2,
+                abort_on_summary_failure=False,
+            )
+        msgs = self._msgs(12)
+        with patch("agent.context_compressor.call_llm", side_effect=err):
+            result = c.compress(msgs, current_tokens=999999, force=True)
+
+        assert result == msgs
+        assert c._last_summary_error == str(err)
+        assert c._last_summary_auth_failure is True
+        assert c._last_compress_aborted is True
+        assert c._last_summary_fallback_used is False
+        assert c._last_summary_dropped_count == 0
+
     def test_402_quota_with_retry_uses_existing_fallback(self):
         """A reset-window quota remains transient instead of aborting compression."""
         err = StubProviderError(

tests/agent/test_manual_compression_feedback.py

@@ -0,0 +1,62 @@
+"""Behavioral coverage for manual compression status messages."""
+
+from types import SimpleNamespace
+
+from agent.manual_compression_feedback import summarize_manual_compression
+
+
+def _messages(count: int) -> list[dict[str, str]]:
+    return [
+        {"role": "user" if index % 2 == 0 else "assistant", "content": str(index)}
+        for index in range(count)
+    ]
+
+
+def test_aborted_compression_reports_preserved_messages_and_reason():
+    messages = _messages(12)
+    state = SimpleNamespace(
+        _last_compress_aborted=True,
+        _last_summary_fallback_used=False,
+        _last_summary_error=(
+            "Provider 'opencode-zen' is set in config.yaml but no API key was found."
+        ),
+    )
+
+    feedback = summarize_manual_compression(
+        messages,
+        list(messages),
+        120_000,
+        120_000,
+        compression_state=state,
+    )
+
+    assert feedback["aborted"] is True
+    assert feedback["fallback_used"] is False
+    assert feedback["headline"] == "Compression aborted: 12 messages preserved"
+    assert "no messages were removed" in feedback["note"]
+    assert "no API key was found" in feedback["note"]
+
+
+def test_fallback_compression_reports_dropped_message_count():
+    before = _messages(12)
+    after = before[:2] + before[-2:]
+    state = SimpleNamespace(
+        _last_compress_aborted=False,
+        _last_summary_fallback_used=True,
+        _last_summary_dropped_count=8,
+        _last_summary_error="summary provider returned an invalid response",
+    )
+
+    feedback = summarize_manual_compression(
+        before,
+        after,
+        120_000,
+        40_000,
+        compression_state=state,
+    )
+
+    assert feedback["aborted"] is False
+    assert feedback["fallback_used"] is True
+    assert feedback["headline"] == "Compressed with fallback: 12 → 4 messages"
+    assert "removed 8 message(s)" in feedback["note"]
+    assert "invalid response" in feedback["note"]