fix: correct task scheduling and simplify agent internals

Fix queue cancellation, concurrency limits and worker status updates.

Use direct Explorer imports, split the Diagnoser loop into helpers and remove unused tool registration and prompt-builder code.

Correct model caching, endpoint selection and retry handling.

artemis/tools/tool_wrapper.py

@@ -13,10 +13,10 @@
 # limitations under the License.
 
 from collections.abc import Callable
+import functools
 import inspect
 import time
 from typing import Annotated, Any, get_args, get_origin
-from unittest.mock import MagicMock, Mock
 import uuid
 
 from langchain_core.messages import ToolMessage
@@ -64,27 +64,19 @@ async def invoke_tool_with_injection(
     """
     final_args = dict(args)
 
-    if isinstance(tool, (Mock, MagicMock)):
-        has_real_coro = hasattr(tool, "coroutine") and not isinstance(
-            tool.coroutine, (Mock, MagicMock)
-        )
-        has_real_func = hasattr(tool, "func") and not isinstance(tool.func, (Mock, MagicMock))
-        if not has_real_coro and not has_real_func:
-            if (
-                state is not None
-                and hasattr(tool, "args")
-                and isinstance(tool.args, dict)
-                and "state" in tool.args
-            ):
-                final_args["state"] = state
-            return await tool.ainvoke(final_args)
+    def _real_callable(candidate: Any) -> Callable | None:
+        """Return a routine or partial whose signature supports direct injection."""
+        target = candidate.func if isinstance(candidate, functools.partial) else candidate
+        if inspect.isroutine(target):
+            return candidate
+        return None
 
     # For StructuredTool, the original function might be in tool.func or tool.coroutine
     func = None
-    if hasattr(tool, "coroutine") and tool.coroutine:
-        func = tool.coroutine
-    elif hasattr(tool, "func") and tool.func:
-        func = tool.func
+    if getattr(tool, "coroutine", None):
+        func = _real_callable(tool.coroutine)
+    if func is None and getattr(tool, "func", None):
+        func = _real_callable(tool.func)
 
     if func:
         try:
@@ -163,7 +155,11 @@ async def invoke_tool_with_injection(
                 )
             CURRENT_TRACE_ID.reset(token)
     else:
-        # Fallback to ainvoke if no direct func available
+        # Fallback to ainvoke if no direct func available; tools that declare
+        # a "state" argument still receive the graph state.
+        tool_args = getattr(tool, "args", None)
+        if state is not None and isinstance(tool_args, dict) and "state" in tool_args:
+            final_args["state"] = state
         return await tool.ainvoke(final_args)