Initial FastAPI admin auth scaffold

app/lib/jwt/blacklist.py

@@ -0,0 +1,25 @@
+import asyncio
+import time
+
+
+class InMemoryTokenBlacklist:
+    def __init__(self) -> None:
+        self._items: dict[str, float] = {}
+        self._lock = asyncio.Lock()
+
+    async def add(self, token: str, ttl: int) -> None:
+        now = time.time()
+        async with self._lock:
+            self._cleanup(now)
+            self._items[token] = now + ttl
+
+    async def has(self, token: str) -> bool:
+        now = time.time()
+        async with self._lock:
+            self._cleanup(now)
+            return token in self._items
+
+    def _cleanup(self, now: float) -> None:
+        expired = [token for token, expires_at in self._items.items() if expires_at <= now]
+        for token in expired:
+            self._items.pop(token, None)