feat: implement Remote WinBox worker, API, frontend integration, OpenBao persistence, and supporting docs

backend/app/schemas/winbox_remote.py

@@ -0,0 +1,63 @@
+"""Request/response schemas for Remote WinBox (Browser) sessions."""
+
+import uuid
+from datetime import datetime
+from enum import Enum
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+class RemoteWinboxState(str, Enum):
+    creating = "creating"
+    active = "active"
+    grace = "grace"
+    terminating = "terminating"
+    terminated = "terminated"
+    failed = "failed"
+
+
+class RemoteWinboxCreateRequest(BaseModel):
+    idle_timeout_seconds: int = Field(default=600, ge=60, le=3600)
+    max_lifetime_seconds: int = Field(default=7200, ge=300, le=14400)
+
+
+class RemoteWinboxSessionResponse(BaseModel):
+    session_id: uuid.UUID
+    status: RemoteWinboxState = RemoteWinboxState.active
+    websocket_path: str
+    expires_at: datetime
+    max_expires_at: datetime
+    idle_timeout_seconds: int
+    max_lifetime_seconds: int
+    xpra_ws_port: Optional[int] = None
+
+
+class RemoteWinboxStatusResponse(BaseModel):
+    session_id: uuid.UUID
+    status: RemoteWinboxState
+    created_at: datetime
+    expires_at: datetime
+    max_expires_at: datetime
+    idle_timeout_seconds: int
+    max_lifetime_seconds: int
+    xpra_ws_port: Optional[int] = None
+
+
+class RemoteWinboxTerminateResponse(BaseModel):
+    session_id: uuid.UUID
+    status: RemoteWinboxState
+    reason: str
+
+
+class RemoteWinboxDuplicateDetail(BaseModel):
+    detail: str = "Active session exists"
+    session: RemoteWinboxStatusResponse
+
+
+class RemoteWinboxSessionItem(BaseModel):
+    """Used in the combined active sessions list."""
+    session_id: uuid.UUID
+    status: RemoteWinboxState
+    created_at: datetime
+    expires_at: datetime