fix: guard all atroposlib imports for CI without atropos installed

- environments/__init__.py: try/except on atroposlib imports so
  submodules like tool_call_parsers remain importable standalone
- test_agent_loop.py, test_tool_call_parsers.py,
  test_managed_server_tool_support.py: skip at module level when
  atroposlib is missing

environments/__init__.py

@@ -18,9 +18,14 @@ Benchmarks (eval-only):
     - benchmarks/terminalbench_2/: Terminal-Bench 2.0 evaluation
 """
 
-from environments.agent_loop import AgentResult, HermesAgentLoop
-from environments.tool_context import ToolContext
-from environments.hermes_base_env import HermesAgentBaseEnv, HermesAgentEnvConfig
+try:
+    from environments.agent_loop import AgentResult, HermesAgentLoop
+    from environments.tool_context import ToolContext
+    from environments.hermes_base_env import HermesAgentBaseEnv, HermesAgentEnvConfig
+except ImportError:
+    # atroposlib not installed — environments are unavailable but
+    # submodules like tool_call_parsers can still be imported directly.
+    pass
 
 __all__ = [
     "AgentResult",

tests/test_agent_loop.py

@@ -18,13 +18,16 @@ import pytest
 # Ensure repo root is importable
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
-from environments.agent_loop import (
-    AgentResult,
-    HermesAgentLoop,
-    ToolError,
-    _extract_reasoning_from_message,
-    resize_tool_pool,
-)
+try:
+    from environments.agent_loop import (
+        AgentResult,
+        HermesAgentLoop,
+        ToolError,
+        _extract_reasoning_from_message,
+        resize_tool_pool,
+    )
+except ImportError:
+    pytest.skip("atroposlib not installed", allow_module_level=True)
 
 
 # ─── Mock server infrastructure ─────────────────────────────────────────

tests/test_managed_server_tool_support.py

@@ -19,6 +19,11 @@ import pytest
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
+try:
+    import atroposlib  # noqa: F401
+except ImportError:
+    pytest.skip("atroposlib not installed", allow_module_level=True)
+
 
 class TestManagedServerAPI:
     """Test that ManagedServer's API matches what hermes-agent expects."""

tests/test_tool_call_parsers.py

@@ -14,12 +14,15 @@ import pytest
 # Ensure repo root is importable
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
-from environments.tool_call_parsers import (
-    ParseResult,
-    ToolCallParser,
-    get_parser,
-    list_parsers,
-)
+try:
+    from environments.tool_call_parsers import (
+        ParseResult,
+        ToolCallParser,
+        get_parser,
+        list_parsers,
+    )
+except ImportError:
+    pytest.skip("atroposlib not installed", allow_module_level=True)
 
 
 # ─── Registry tests ─────────────────────────────────────────────────────