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

apps/admin_console/database/connection.py

@@ -15,7 +15,6 @@
 from contextlib import contextmanager
 from pathlib import Path
 import sqlite3
-from fastapi import HTTPException
 
 try:
     from admin_console.core.config import DB_PATH
@@ -23,13 +22,29 @@ except ImportError:
     from apps.admin_console.core.config import DB_PATH
 
 
+_initialized_dbs = set()
+
+
 def get_db(db_path: Path | None = None) -> sqlite3.Connection:
     """Returns a SQLite connection with timeout and Row row_factory."""
     path = db_path or DB_PATH
-    if not path.exists():
-        raise HTTPException(status_code=500, detail=f"Database not found at {path}")
+    path_key = str(path)
+    if path_key not in _initialized_dbs:
+        path.parent.mkdir(parents=True, exist_ok=True)
+        try:
+            from artemis.data_engine.storage import StorageManager
+
+            StorageManager(db_path=path, base_trace_dir=path.parent)
+            _initialized_dbs.add(path_key)
+        except Exception:
+            pass
     conn = sqlite3.connect(path, timeout=10.0)
     conn.row_factory = sqlite3.Row
+    try:
+        conn.execute("PRAGMA journal_mode=WAL")
+        conn.execute("PRAGMA busy_timeout=10000")
+    except Exception:
+        pass
     return conn