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"]