Add admin panel, WebSocket support, and API versioning

Introduce an admin portal (React + Nginx), WebSocket routing, and
API versioning middleware with `/api/v1/` prefix deprecation.
Add master API key authentication, new Prometheus metrics for AI
token consumption and active WebSockets, and extend S3 config
with a public endpoint URL. Update test paths and fixtures to
align with the new routing structure.

sdk/imago_client/resources/auth.py

@@ -0,0 +1,34 @@
+"""
+Client API keys management (requires admin scope)
+"""
+from typing import Any, Dict
+from httpx import AsyncClient
+
+from ..utils import with_retry
+
+class AuthResource:
+    """Resource for administering client accounts (admin only)."""
+    def __init__(self, client: AsyncClient):
+        self._client = client
+
+    async def _handle_request(self, method: str, path: str, **kwargs) -> Any:
+        async def _req():
+             resp = await self._client.request(method, path, **kwargs)
+             resp.raise_for_status()
+             return resp.json()
+        return await with_retry(_req)
+
+    async def create_client(self, name: str, is_premium: bool = False, scopes: list[str] = None) -> Dict[str, Any]:
+         data = {"name": name, "is_premium": is_premium}
+         if scopes:
+             data["scopes"] = scopes
+         return await self._handle_request("POST", "/api/v1/auth/clients", json=data)
+    
+    async def list_clients(self) -> list[Dict[str, Any]]:
+         return await self._handle_request("GET", "/api/v1/auth/clients")
+         
+    async def rotate_key(self, client_id: str) -> Dict[str, str]:
+         return await self._handle_request("POST", f"/api/v1/auth/clients/{client_id}/rotate-key")
+
+    async def delete_client(self, client_id: str) -> None:
+         await self._handle_request("DELETE", f"/api/v1/auth/clients/{client_id}")