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/agents/explorer/perception_tools.py

@@ -19,9 +19,7 @@ group plus its search helpers, packaged as a mixin consumed by ``Explorer``.
 Text search, the coordinate audit and the OCR inventory all answer from the
 run's in-memory :class:`~artemis.agents.explorer.screen_index.ScreenIndex`;
 no Data Engine round trip is involved, so an unsynced frame never degrades
-to "no UI data".  Patched collaborators (``settings``, ``draw_dots``,
-``_run_object_detection``, ``logger``) are resolved through the facade module
-at call time; see ``artemis.agents.explorer._facade``.
+to "no UI data".
 """
 
 import asyncio
@@ -33,11 +31,16 @@ from typing import TYPE_CHECKING, Any
 
 import cv2
 
-from artemis.agents.explorer._facade import facade
 from artemis.agents.explorer.geometry import norm_to_pixel, pixel_to_norm
 from artemis.agents.explorer.screen_index import ScreenElement, ScreenIndex, normalize_text
 from artemis.agents.image_processor.image_processor import ImageProcessor
+from artemis.agents.object_detector.object_detector import _run_object_detection
+from artemis.config import settings
 from artemis.data_engine.trace import trace
+from artemis.utils.logger import get_logger
+from artemis.utils.visualization import draw_dots
+
+logger = get_logger(__name__)
 
 #: Text-search answer when the screen could not be indexed at all.
 NO_UI_TREE_MESSAGE = "No UI-tree data is available for this screen; rely on visual detection."
@@ -49,7 +52,6 @@ def load_detector_templates() -> tuple[list[str], float]:
     Shared by ``exec_detect_objects`` and the flash-mode ``run`` path; the two
     call sites historically carried an identical inline copy of this block.
     """
-    _ex = facade()
     detector_prompt_path = Path(__file__).parent.parent / "object_detector" / "object_detector.json"
     global_timeout = 30.0
     try:
@@ -61,7 +63,7 @@ def load_detector_templates() -> tuple[list[str], float]:
         if isinstance(raw_timeout, (int, float)) and raw_timeout > 0:
             global_timeout = float(raw_timeout)
     except Exception as e:
-        _ex.logger.warning(f"Failed to load detector prompt config: {e}")
+        logger.warning(f"Failed to load detector prompt config: {e}")
         detector_templates = ["Point to the following objects in the provided image: {labels_str}."]
         detector_instructions = ""
 
@@ -127,8 +129,7 @@ class PerceptionToolsMixin:
 
     def _next_output_path(self, subdir: str) -> Path:
         """Next free ``images/<subdir>/<image>_<n>.jpg`` under the traces directory."""
-        _ex = facade()
-        out_dir = Path(_ex.settings.TRACES_PATH) / "images" / subdir
+        out_dir = Path(settings.TRACES_PATH) / "images" / subdir
         out_dir.mkdir(parents=True, exist_ok=True)
         stem = self.image_name or "temp_image"
         max_seq = 0
@@ -147,15 +148,14 @@ class PerceptionToolsMixin:
         textual result is still delivered, so one bad annotation never sinks
         the tool call.
         """
-        _ex = facade()
         if not self.screenshot_path:
             return None
         try:
             output_path = self._next_output_path(subdir)
-            _ex.draw_dots(self.screenshot_path, points, labels, str(output_path), color=color)
+            draw_dots(self.screenshot_path, points, labels, str(output_path), color=color)
             return str(output_path)
         except Exception as e:
-            _ex.logger.warning(f"Failed to draw {subdir} dots: {e}")
+            logger.warning(f"Failed to draw {subdir} dots: {e}")
             return None
 
     # ------------------------------------------------------------------ #
@@ -237,7 +237,6 @@ class PerceptionToolsMixin:
         prefix: str = "D",
         color: str = "red",
     ) -> dict:
-        _ex = facade()
         try:
             if not self.screenshot_path:
                 return {
@@ -257,7 +256,7 @@ class PerceptionToolsMixin:
             # Load object detector templates
             templates, global_timeout = load_detector_templates()
 
-            result = await _ex._run_object_detection(
+            result = await _run_object_detection(
                 self.ctx,
                 target_path,
                 queries,
@@ -280,7 +279,7 @@ class PerceptionToolsMixin:
                         "image_path": str(target_path),
                     }
 
-                base_dir = _ex.settings.TRACES_PATH
+                base_dir = settings.TRACES_PATH
                 images_dir = base_dir / "images"
                 object_detect_dir = images_dir / "object_detect"
                 object_detect_dir.mkdir(parents=True, exist_ok=True)
@@ -341,7 +340,7 @@ class PerceptionToolsMixin:
                             f'[{label_id}] "{item.get("label")}" at [{x_orig_norm},{y_orig_norm}]'
                         )
 
-                _ex.draw_dots(
+                draw_dots(
                     self.screenshot_path,
                     points,
                     d_labels,
@@ -361,7 +360,7 @@ class PerceptionToolsMixin:
                 }
 
             except Exception as e:
-                _ex.logger.warning(f"Failed to process detection output for annotation: {e}")
+                logger.warning(f"Failed to process detection output for annotation: {e}")
                 return {"text": str(result), "image_path": None}
         except Exception as e:
             return {
@@ -569,7 +568,6 @@ class PerceptionToolsMixin:
         y_max: int,
         zoom_factor: float = 2.0,
     ) -> dict:
-        _ex = facade()
         try:
             if not self.screenshot_path:
                 return {
@@ -613,7 +611,7 @@ class PerceptionToolsMixin:
                 if new_w > 0 and new_h > 0:
                     cropped = cv2.resize(cropped, (new_w, new_h))
 
-            base_dir = _ex.settings.TRACES_PATH
+            base_dir = settings.TRACES_PATH
             images_dir = base_dir / "images"
             inspect_region_dir = images_dir / "inspect_region"
             inspect_region_dir.mkdir(parents=True, exist_ok=True)