feat(console): add Artemis Admin & Trace Console backend and management plane

Introduces the comprehensive developer/administrator control plane and trace
inspection console backend for the ARTEMIS mobile automation platform.

Key Features & Backend Architecture:
- Core Server & Modular Routing:
  * FastAPI modular architecture with dedicated routers for sessions, steps, tasks, media, stream, and replay.
  * Multi-layer repository pattern with SQLite persistence for sessions, traces, and step data.
- Task Control & Queue Management:
  * FIFO asynchronous task queue service with support for single/batch goal execution and profile selection (Flash / Pro).
  * Session lifecycle controls (run, pause, resume, stop, clear queue).
  * Startup orphan cleanup and automatic older replay archiving.
- Live Telemetry & IPC Communication:
  * High-performance IPC server for streaming real-time execution logs, agent thoughts, and tool invocations.
  * Server-Sent Events (SSE) /api/stream/{session_id} endpoint for live UI updates.
- Real-Time Device Streaming:
  * Live ADB screen capture and MJPEG frame generator (/api/stream/device-live).
  * Device connectivity and state inspection endpoint (/api/stream/device-state).
- Trace Inspection & Step Replay Engine:
  * Hierarchical call tree inspection, pre/post step screenshots, and action overlay metadata.
  * Isolated single-step replay manager (/api/replay) for interactive debugging and validation.

apps/admin_console/routers/stream.py

@@ -0,0 +1,56 @@
+# 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.
+
+"""Device Screen Live Streaming Router.
+
+Exposes real-time screen streaming endpoints for the Web UI.
+"""
+
+from fastapi import APIRouter
+from fastapi.responses import JSONResponse, StreamingResponse
+
+try:
+    from admin_console.services.device_stream_service import device_stream_service
+except ImportError:
+    from apps.admin_console.services.device_stream_service import device_stream_service
+
+router = APIRouter(tags=["stream"])
+
+
+@router.get("/api/stream/device-live")
+async def stream_device_live():
+    """Streams live device screen frames as multipart MJPEG."""
+    return StreamingResponse(
+        device_stream_service.mjpeg_frame_generator(),
+        media_type="multipart/x-mixed-replace; boundary=frame",
+        headers={
+            "Cache-Control": "no-cache, no-store, must-revalidate, max-age=0",
+            "Pragma": "no-cache",
+            "Expires": "0",
+            "Connection": "keep-alive",
+        },
+    )
+
+
+@router.get("/api/stream/device-state")
+async def get_device_stream_state():
+    """Returns whether an ADB device is connected and live streaming is available."""
+    serial = await device_stream_service.get_device_serial()
+    return JSONResponse(
+        {
+            "connected": serial is not None,
+            "serial": serial,
+            "live_stream_url": "/api/stream/device-live" if serial else None,
+        }
+    )