feat(auth): add local login, audit, API keys, and system admin UI

Gate netx Web/API/WebCRT with JWT and per-user API tokens, bootstrap an admin with forced password change, and expose users/audit/API-key management under a System section. MCP can reuse data/auth/mcp_token without extra env for local labs.

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

netx_api/auth_tokens.py

@@ -0,0 +1,62 @@
+"""JWT access tokens and opaque API token hashing."""
+
+from __future__ import annotations
+
+import hashlib
+import logging
+import secrets
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+import jwt
+
+from .config import settings
+
+_log = logging.getLogger("netx.auth")
+
+_DEFAULT_DEV_SECRET = "netx-dev-auth-secret-change-me-in-production-32b"
+_warned_default_secret = False
+
+
+def auth_secret() -> str:
+    """Return configured secret (lab default is set in Settings)."""
+    global _warned_default_secret
+    configured = str(settings.auth_secret or "").strip() or _DEFAULT_DEV_SECRET
+    if configured == _DEFAULT_DEV_SECRET and not _warned_default_secret:
+        _warned_default_secret = True
+        _log.warning(
+            "using default NETX_AUTH_SECRET; set a unique secret for production deployments"
+        )
+    return configured
+
+
+def issue_access_token(*, user_id: str, username: str, role: str) -> str:
+    ttl = max(300, int(settings.auth_token_ttl_sec or 86400))
+    now = datetime.now(timezone.utc)
+    payload = {
+        "sub": str(user_id),
+        "username": str(username),
+        "role": str(role),
+        "typ": "access",
+        "iat": int(now.timestamp()),
+        "exp": int((now + timedelta(seconds=ttl)).timestamp()),
+    }
+    return jwt.encode(payload, auth_secret(), algorithm="HS256")
+
+
+def decode_access_token(token: str) -> dict[str, Any]:
+    return jwt.decode(
+        str(token or ""),
+        auth_secret(),
+        algorithms=["HS256"],
+        options={"require": ["exp", "sub"]},
+    )
+
+
+def new_api_token_plaintext() -> str:
+    """Generate opaque API token (shown once). Prefix helps ops identify netx tokens."""
+    return "nxt_" + secrets.token_urlsafe(32)
+
+
+def hash_api_token(plaintext: str) -> str:
+    return hashlib.sha256(str(plaintext or "").encode("utf-8")).hexdigest()