feat: implement robust multi-tier text input architecture and ADB diagnostics

- Android Text Input & IME Normalization:
  - Implement progressive 3-tier input architecture in AndroidAdbDriver and AndroidDeviceController:
    - Tier 1 (Primary): Zero-dependency clipboard injection + KEYCODE_PASTE (immune to IME Pinyin interception, full Unicode/Emoji support, preserves multiline formatting).
    - Tier 2 (Broadcast): Base64 broadcast injection when ADBKeyboard is active.
    - Tier 3 (Fallback): Native ADB physical keyevent fallback.
  - Add literal newline normalization (\r\n, \n, \r) to prevent JSON escape string corruption (e.g. '10086\n' -> '10086、n').
  - Add set_clipboard method to UIAutomatorClient without auxiliary APK requirements.

- Diagnostics & System Probes:
  - Add adb_keys diagnostics probe for ADB key auth checks.
  - Integrate diagnostics into CLI doctor command.

- Admin Console & Showcase UI:
  - Improve model service and system router in admin console.
  - Enhance workspace stream view and session state in showcase UI.

apps/admin_console/routers/system.py

@@ -63,6 +63,17 @@ async def restart_adb_server():
     }
 
 
+@router.post("/adb/heal-keys")
+async def heal_adb_keys():
+    """Auto-heal corrupted ADB authentication RSA keys and return updated readiness."""
+    heal_result = await readiness_engine.heal_adb_keys()
+    updated_report = await readiness_engine.run_all()
+    return {
+        "heal_result": heal_result,
+        "report": updated_report,
+    }
+
+
 class ConnectAdbRequest(BaseModel):
     """Payload to connect to an Android device over Wi-Fi."""