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/repositories/session_repository.py

@@ -33,13 +33,6 @@ class SessionRepository:
             cursor.execute("SELECT * FROM sessions ORDER BY start_time DESC")
             return [dict(r) for r in cursor.fetchall()]
 
-    def get_session_by_id(self, session_id: str) -> dict[str, Any] | None:
-        with db_session(self.db_path) as conn:
-            cursor = conn.cursor()
-            cursor.execute("SELECT * FROM sessions WHERE session_id = ?", (str(session_id),))
-            row = cursor.fetchone()
-            return dict(row) if row else None
-
     def get_video_recordings_map(self) -> dict[str, str]:
         with db_session(self.db_path) as conn:
             cursor = conn.cursor()