fix: Add uptime sync to all tools for 5s HMAC replay window

All three standalone tools (esp-cmd, esp-fleet, esp-ota) now fetch
device uptime before signing commands, matching what esp-ctl already
does. Includes 60ms delay after uptime fetch to avoid firmware rate
limiter (50ms inter-command throttle).

tools/esp-fleet

@@ -10,7 +10,7 @@ import sys
 import threading
 import time
 
-from esp_ctl.auth import sign_command
+from esp_ctl.auth import get_secret, sign_command
 
 DEFAULT_PORT = 5501
 DEFAULT_HTTP_PORT = 8070
@@ -53,15 +53,37 @@ Examples:
   esp-fleet ota --parallel /path/to/firmware.bin"""
 
 
+def _get_uptime(ip, timeout=TIMEOUT):
+    """Query device uptime_s for HMAC timestamp (unauthenticated)."""
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.settimeout(timeout)
+    try:
+        sock.sendto(b"STATUS", (ip, DEFAULT_PORT))
+        data, _ = sock.recvfrom(1500)
+        for part in data.decode().split():
+            if part.startswith("uptime_s="):
+                return int(part.split("=", 1)[1])
+    except (socket.timeout, OSError, ValueError):
+        pass
+    finally:
+        sock.close()
+    return 0
+
+
 def query(name, host, cmd):
     """Send command to one sensor, return (name, reply_or_error)."""
-    cmd = sign_command(cmd)
     try:
         info = socket.getaddrinfo(host, DEFAULT_PORT, socket.AF_INET, socket.SOCK_DGRAM)
         ip = info[0][4][0]
     except socket.gaierror:
         return (name, f"ERR: cannot resolve {host}")
 
+    secret = get_secret()
+    uptime = _get_uptime(ip) if secret else 0
+    if secret and uptime:
+        time.sleep(0.06)  # avoid firmware rate limiter (50ms)
+    cmd = sign_command(cmd, uptime, secret)
+
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     sock.settimeout(TIMEOUT)
     try:
@@ -87,7 +109,11 @@ def _resolve(host):
 
 def _udp_cmd(ip, cmd, timeout=TIMEOUT):
     """Send signed UDP command and return reply string."""
-    cmd = sign_command(cmd)
+    secret = get_secret()
+    uptime = _get_uptime(ip, timeout) if secret else 0
+    if secret and uptime:
+        time.sleep(0.06)  # avoid firmware rate limiter (50ms)
+    cmd = sign_command(cmd, uptime, secret)
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     sock.settimeout(timeout)
     try: