feat: Add configurable stale_timeout for APRS-IS connections

Add a new 'stale_timeout' configuration option to the aprs_network config
group that allows users to customize how long to wait before considering
an APRS-IS connection stale.

Problem:
The stale connection threshold was hardcoded to 2 minutes. In environments
with frequent network hiccups or when using certain APRS-IS servers that
may drop connections silently, 2 minutes can be too long to wait before
reconnecting, resulting in significant data loss.

Solution:
- Add 'stale_timeout' option to aprsd/conf/client.py with default of 120s
- Update APRSISDriver.__init__ to use the config value
- Maintain backward compatibility by defaulting to 120s if not configured
- Update tests to handle the new configuration option

Usage:
  [aprs_network]
  stale_timeout = 60  # Reconnect after 60 seconds without data

The default remains 120 seconds (2 minutes) for backward compatibility.

aprsd/client/drivers/aprsis.py

@@ -32,8 +32,12 @@ class APRSISDriver:
     connected = False
 
     def __init__(self):
-        max_timeout = {'hours': 0.0, 'minutes': 2, 'seconds': 0}
-        self.max_delta = datetime.timedelta(**max_timeout)
+        # Use configurable stale_timeout, defaulting to 120 seconds if not set
+        try:
+            stale_timeout = CONF.aprs_network.stale_timeout
+        except (cfg.NoSuchOptError, cfg.NoSuchGroupError):
+            stale_timeout = 120  # Default to 2 minutes for backward compatibility
+        self.max_delta = datetime.timedelta(seconds=stale_timeout)
         self.login_status = {
             'success': False,
             'message': None,

aprsd/conf/client.py

@@ -47,6 +47,14 @@ aprs_opts = [
         default=14580,
         help='APRS-IS port',
     ),
+    cfg.IntOpt(
+        'stale_timeout',
+        default=120,
+        help='Seconds without receiving data before connection is considered stale. '
+        'When a connection goes stale, it will be automatically reconnected. '
+        'Lower values detect dead connections faster but may cause unnecessary '
+        'reconnects during brief network hiccups. Default is 120 seconds (2 minutes).',
+    ),
 ]
 
 kiss_serial_opts = [

tests/client/drivers/test_aprsis_driver.py

@@ -24,6 +24,7 @@ class TestAPRSISDriver(unittest.TestCase):
         self.mock_conf.aprs_network.password = '12345'
         self.mock_conf.aprs_network.host = 'rotate.aprs.net'
         self.mock_conf.aprs_network.port = 14580
+        self.mock_conf.aprs_network.stale_timeout = 120  # Default 2 minutes
 
         # Mock APRS Lib Client
         self.aprslib_patcher = mock.patch('aprsd.client.drivers.aprsis.APRSLibClient')
@@ -71,11 +72,23 @@ class TestAPRSISDriver(unittest.TestCase):
     def test_init(self):
         """Test initialization sets default values."""
         self.assertIsInstance(self.driver.max_delta, datetime.timedelta)
-        self.assertEqual(self.driver.max_delta, datetime.timedelta(minutes=2))
+        # Default stale_timeout is 120 seconds (2 minutes)
+        self.assertEqual(self.driver.max_delta, datetime.timedelta(seconds=120))
         self.assertFalse(self.driver.login_status['success'])
         self.assertIsNone(self.driver.login_status['message'])
         self.assertIsNone(self.driver._client)
 
+    def test_init_custom_stale_timeout(self):
+        """Test initialization with custom stale_timeout."""
+        # Set a custom stale_timeout
+        self.mock_conf.aprs_network.stale_timeout = 60  # 1 minute
+
+        # Create a new driver instance with custom timeout
+        driver = APRSISDriver.__new__(APRSISDriver)
+        driver.__init__()
+
+        self.assertEqual(driver.max_delta, datetime.timedelta(seconds=60))
+
     def test_is_enabled_true(self):
         """Test is_enabled returns True when APRS-IS is enabled."""
         self.mock_conf.aprs_network.enabled = True