van-leds fix round 2: state_max_age_s default 180, non-finite/invalid config guards, log-recurrence test

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KqhjP7nud5gdBg25zCiRk9

leds/van-leds

@@ -19,6 +19,7 @@ keys: "sysfs_leds", "sysfs_net", "failover_state".
 """
 
 import json
+import math
 import os
 import signal
 import sys
@@ -33,7 +34,7 @@ DEFAULTS = {
     "sysfs_leds": "/sys/class/leds",
     "sysfs_net": "/sys/class/net",
     "failover_state": "/run/van-failover/state.json",
-    "state_max_age_s": 60,      # older failover state is ignored (wired-uplink fallback)
+    "state_max_age_s": 180,     # older failover state is ignored (wired-uplink fallback); van-failover rewrites it every ~61-65 s
 }
 LED_KEYS = (("power", "led_power"), ("lan", "led_lan"), ("wan", "led_wan"), ("wlan", "led_wlan"))
 
@@ -60,9 +61,18 @@ def clear_log(key):
 
 def interval(cfg):
     try:
-        return max(1.0, float(cfg["poll_interval_s"]))
+        v = float(cfg["poll_interval_s"])
     except (TypeError, ValueError):
         return 5.0
+    return max(1.0, v) if math.isfinite(v) else 5.0
+
+
+def max_age(cfg):
+    try:
+        v = float(cfg["state_max_age_s"])
+    except (TypeError, ValueError):
+        return 180.0
+    return v if math.isfinite(v) else 180.0
 
 
 def load_config(path):
@@ -98,7 +108,7 @@ def state_stale(state, now, max_age):
     return now - t > max_age
 
 
-def desired_wan(state, uplink_carrier, uplink=None, now=None, max_age=60):
+def desired_wan(state, uplink_carrier, uplink=None, now=None, max_age=180):
     """-> ("netdev", device) | ("heartbeat", None) | ("none", None). `now`: epoch seconds (default: clock)."""
     if isinstance(state, dict) and state_stale(state, time.time() if now is None else now, max_age):
         state = None
@@ -151,7 +161,7 @@ def carrier(cfg, iface):
 def wanted(cfg, now=None):
     """{role: (trigger, device)} for every role (before skipping absent LEDs)."""
     wan = desired_wan(load_state(cfg["failover_state"]), carrier(cfg, cfg["uplink_iface"]),
-                      cfg["uplink_iface"] or None, now, cfg["state_max_age_s"])
+                      cfg["uplink_iface"] or None, now, max_age(cfg))
     return {
         "power": ("default-on", None),
         "lan": ("netdev", cfg["lan_iface"]),