feat: initial HSAP platform

Huaxu Sentinel Active Safety Platform with embedded algorithm code,
Docker Compose setup, and vendored dataset scaffolds for clone-and-run.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/as_platform/auth/jwt.py

@@ -0,0 +1,29 @@
+"""JWT 令牌。"""
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+from jose import JWTError, jwt
+
+from as_platform.config import JWT_EXPIRE_HOURS, JWT_SECRET
+
+ALGORITHM = "HS256"
+
+
+def create_access_token(user_id: int, extra: dict[str, Any] | None = None) -> str:
+    payload = {
+        "sub": str(user_id),
+        "exp": datetime.now(timezone.utc) + timedelta(hours=JWT_EXPIRE_HOURS),
+        "iat": datetime.now(timezone.utc),
+    }
+    if extra:
+        payload.update(extra)
+    return jwt.encode(payload, JWT_SECRET, algorithm=ALGORITHM)
+
+
+def decode_access_token(token: str) -> dict[str, Any] | None:
+    try:
+        return jwt.decode(token, JWT_SECRET, algorithms=[ALGORITHM])
+    except JWTError:
+        return None