Initial commit: LAN Checker

Network health monitoring script with MQTT reporting for Home Assistant.
- Ping, HTTP, and SNMP checkers
- MQTT Discovery for automatic entity creation
- Configurable check intervals

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

checkers/http.py

@@ -0,0 +1,53 @@
+import time
+
+import requests
+
+from .base import BaseChecker, CheckResult
+
+
+class HttpChecker(BaseChecker):
+    def check(self) -> CheckResult:
+        url = self.config["url"]
+        method = self.config.get("method", "GET").upper()
+        timeout = self.config.get("timeout", 10)
+        expected_status = self.config.get("expected_status", 200)
+        verify_ssl = self.config.get("verify_ssl", True)
+        headers = self.config.get("headers", {})
+
+        start = time.time()
+        try:
+            response = requests.request(
+                method=method,
+                url=url,
+                timeout=timeout,
+                verify=verify_ssl,
+                headers=headers
+            )
+            response_time = (time.time() - start) * 1000  # ms
+
+            if response.status_code == expected_status:
+                return CheckResult(
+                    success=True,
+                    message=f"HTTP {response.status_code}",
+                    response_time=response_time,
+                    details={"status_code": response.status_code}
+                )
+            else:
+                return CheckResult(
+                    success=False,
+                    message=f"Unexpected status: {response.status_code} (expected {expected_status})",
+                    response_time=response_time,
+                    details={"status_code": response.status_code}
+                )
+        except requests.Timeout:
+            return CheckResult(
+                success=False,
+                message="HTTP timeout",
+                response_time=None
+            )
+        except requests.RequestException as e:
+            return CheckResult(
+                success=False,
+                message=f"HTTP error: {e}",
+                response_time=None
+            )