feat: introduce MCP server, cross-platform runtime, and Showcase UI reorganization

- Showcase UI Reorganization:
  * Move web UI dashboard from root directory into apps/showcase_ui/ for cleaner project structure
  * Add 'artemis ui' CLI command (artemis/interfaces/cli/commands/ui.py) and launcher scripts for the interactive showcase console
- Standalone MCP Server & Notifiers (mcp_server/):
  * Implement dedicated MCP server package with mobile automation tools (device_state, inspect_trace, task_manager, task_runner)
  * Add multi-channel notifiers (AgentAPI, Desktop notifications, Webhooks, File output, and Composite routing)
  * Introduce background task runner and trace store for autonomous mobile execution monitoring
- Cross-Platform Runtime & Toolchain Support:
  * Add artemis/platform/ with OS-specific implementations for Linux, macOS (Darwin), and Windows
  * Add artemis/runtime/supervisor.py for resilient process and agent runtime supervision
  * Add artemis/toolchain/ with dependency resolution and SDK descriptors
  * Add cross-platform launcher scripts (start.sh, start.bat) and installer scripts (scripts/install_deps.*)
- Core Enhancements & Diagnostics:
  * Enhance coordinate normalization, OCR API fallback, and perception pipeline
  * Add credential validation (credentials_validator.py) and system diagnostics
  * Update bilingual documentation (README.md, README_CN.md) and architecture diagrams
- Test Suite Expansion:
  * Add integration tests for cloud gateway, remote ADB, and Artemis login
  * Add unit tests covering core diagnostics, platform detection, toolchain, credentials validator, optional OCR, and MCP tools

tests/unit/agents/test_explorer.py

@@ -50,7 +50,7 @@ async def test_explorer_run():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/test_screenshot.jpg"
@@ -138,7 +138,7 @@ async def test_explorer_submit_answer():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/test_screenshot.jpg"
@@ -226,7 +226,7 @@ async def test_explorer_submit_answer_self_correction():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/test_screenshot.jpg"
@@ -380,7 +380,7 @@ async def test_explorer_initial_visual_marking():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/test_screenshot.jpg"
@@ -466,7 +466,7 @@ async def test_explorer_initial_visual_marking_previous_screenshot():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     # current screenshot is different
@@ -559,7 +559,7 @@ async def test_explorer_initial_visual_marking_previous_screenshot_no_ui_tree():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/current_screenshot.jpg"
@@ -641,7 +641,7 @@ async def test_explorer_initial_visual_marking_previous_screenshot_ocr_fusion():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/current_screenshot.jpg"
@@ -743,7 +743,7 @@ async def test_explorer_initial_visual_marking_previous_screenshot_on_the_fly_oc
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/current_screenshot.jpg"
@@ -816,6 +816,10 @@ async def test_explorer_initial_visual_marking_previous_screenshot_on_the_fly_oc
             new_callable=AsyncMock,
             return_value=mock_ocr_result,
         ) as mock_perform_ocr,
+        patch(
+            "artemis.agents.explorer.explorer.is_ocr_configured",
+            return_value=True,
+        ),
         patch("artemis.agents.explorer.explorer.draw_dots") as mock_draw_dots,
         patch("pathlib.Path.exists", return_value=True),
         patch("pathlib.Path.read_text", return_value=mock_prompt),
@@ -853,7 +857,7 @@ async def test_explorer_denylisted_tool():
     mock_ctx.data_engine.base_dir = "/tmp/test_session"
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
     mock_ctx.agent_config = MagicMock()
     mock_ctx.agent_config.denylisted_tools = {"explorer": ["search_xml_ocr"]}
 
@@ -1048,7 +1052,7 @@ async def test_explorer_final_turn_tool_stripping():
 
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.explorer = MagicMock()
-    mock_ctx.llm_config.explorer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.explorer.model = "gemini-3.7-flash"
 
     mock_state = MagicMock(spec=State)
     mock_state.latest_screenshot = "/tmp/test_screenshot.jpg"
@@ -1212,7 +1216,7 @@ async def test_explorer_ask_perception_tool():
             detect_queries=["profile icon"],
         )
 
-        assert "XML/OCR Text Search Results are:" in result["text"]
+        assert "Text Search Results are:" in result["text"]
         assert "Coordinate Search Results are:" in result["text"]
         assert "Object Detection Results are:" in result["text"]
 

tests/unit/agents/test_failure_analyzer_tools.py

@@ -339,7 +339,7 @@ async def test_swipe_happy_path_direction(mock_context, mock_controller):
         ctx=mock_context,
     )
     assert "Swipe completed successfully" in outcome
-    mock_controller.swipe_coords.assert_called_once_with(648, 1920, 648, 480, 400)
+    mock_controller.swipe_coords.assert_called_once_with(648, 1680, 648, 720, 400)
 
 
 @pytest.mark.asyncio

tests/unit/agents/test_operator.py

@@ -158,7 +158,7 @@ async def test_perform_action_validation():
     assert err is None
     assert actions[0]["action"] == "swipe"
     assert len(actions[0]["coordinates"]) == 4
-    assert actions[0]["duration"] == 380
+    assert actions[0]["duration"] == 800
 
     # Test click with float target index (coercion)
     actions, err = node._translate_and_validate_tool(
@@ -1547,7 +1547,7 @@ async def test_operator_swipe_translation():
     assert err is None
     assert len(actions) == 1
     assert actions[0]["action"] == "swipe"
-    assert actions[0]["coordinates"] == [648, 1920, 648, 480]
+    assert actions[0]["coordinates"] == [648, 1680, 648, 720]
 
     # 2. Start & End coordinate swipe (drag)
     actions, err = node._translate_and_validate_tool(
@@ -1587,4 +1587,4 @@ async def test_operator_swipe_translation():
     assert err is None
     assert len(actions) == 1
     assert actions[0]["action"] == "swipe"
-    assert actions[0]["coordinates"] == [648, 480, 648, 1920]
+    assert actions[0]["coordinates"] == [648, 720, 648, 1680]

tests/unit/agents/test_plan_mutation_guardrails.py

@@ -0,0 +1,87 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest.mock import MagicMock
+from artemis.graph.graph import check_plan_mutation_rejections
+from artemis.graph.state import State
+
+
+def test_check_plan_mutation_incomplete_nested():
+    content_before = "- [/] Main task\n  - [ ] Subtask 1"
+    content_after = "- [x] Main task\n  - [ ] Subtask 1"
+    res = check_plan_mutation_rejections(content_before, content_after)
+    assert res is not None
+    assert "goals in the task plan that have not been marked as completed" in res
+
+
+def test_check_plan_mutation_delete_continuous_loop():
+    content_before = (
+        "- [x] Open app\n"
+        "- [/] [Loop] Periodically monitor for new emails "
+        "(Exit: Continuous monitoring until manually stopped; Interval: every 5 minutes)\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    content_after = (
+        "- [x] Open app\n"
+        "- [x] Monitor for new emails\n"
+        "  - [x] Baseline established\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    res = check_plan_mutation_rejections(content_before, content_after)
+    assert res is not None
+    assert "cannot delete an active [Loop]" in res
+
+
+def test_check_plan_mutation_mark_continuous_loop_completed():
+    content_before = (
+        "- [x] Open app\n"
+        "- [/] [Loop] Periodically monitor for new emails "
+        "(Exit: Continuous monitoring until manually stopped; Interval: every 5 minutes)\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    content_after = (
+        "- [x] Open app\n"
+        "- [x] [Loop] Periodically monitor for new emails "
+        "(Exit: Continuous monitoring until manually stopped; Interval: every 5 minutes)\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    res = check_plan_mutation_rejections(content_before, content_after)
+    assert res is not None
+    assert "cannot be unilaterally marked as completed [x]" in res
+
+
+def test_check_plan_mutation_user_stopped_allowed():
+    content_before = (
+        "- [x] Open app\n"
+        "- [/] [Loop] Periodically monitor for new emails "
+        "(Exit: Continuous monitoring until manually stopped; Interval: every 5 minutes)\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    content_after = (
+        "- [x] Open app\n"
+        "- [x] [Loop] Periodically monitor for new emails "
+        "(Exit: Continuous monitoring until manually stopped; Interval: every 5 minutes)\n"
+        "  - [x] Polling Check #1: Done"
+    )
+    state = MagicMock(spec=State)
+    state.injected_instruction = "Please stop the task now."
+    res = check_plan_mutation_rejections(content_before, content_after, state=state)
+    assert res is None
+
+
+def test_check_plan_mutation_normal_bounded_task():
+    content_before = "- [ ] Open Settings\n- [ ] Toggle WiFi"
+    content_after = "- [x] Open Settings\n- [x] Toggle WiFi"
+    res = check_plan_mutation_rejections(content_before, content_after)
+    assert res is None

tests/unit/agents/test_video_analyzer.py

@@ -28,7 +28,7 @@ async def test_video_analyzer_run():
     mock_ctx.data_engine = None
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.utils.video_analyzer = MagicMock()
-    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.7-flash"
 
     # Mock Gemini Client
     mock_client = MagicMock()
@@ -79,7 +79,7 @@ async def test_video_analyzer_preserves_thought_signature():
     mock_ctx.data_engine = None
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.utils.video_analyzer = MagicMock()
-    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.7-flash"
 
     # Mock MobileDeviceController
     mock_controller = MagicMock()
@@ -255,7 +255,7 @@ async def test_video_analyzer_sub_agent_confidence_validation():
     mock_ctx.data_engine = None
     mock_ctx.llm_config = MagicMock()
     mock_ctx.llm_config.utils.video_analyzer = MagicMock()
-    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.6-flash"
+    mock_ctx.llm_config.utils.video_analyzer.model = "gemini-3.7-flash"
 
     # Mock MobileDeviceController
     mock_controller = MagicMock()