debug: add detailed logging to health check endpoint

Added logging to identify which component is failing health checks:
- Log database and Redis status on each health check
- Log Redis errors with full error details
- This will help diagnose the production 503 errors

lib/towerops_web/controllers/health_controller.ex

@@ -7,9 +7,14 @@ defmodule ToweropsWeb.HealthController do
   alias Towerops.Repo
 
   def index(conn, _params) do
+    require Logger
+
     db_status = check_database()
     redis_status = check_redis()
 
+    # Log health check results for debugging
+    Logger.debug("Health check: db=#{inspect(db_status)}, redis=#{inspect(redis_status)}")
+
     all_healthy = db_status == :ok and redis_status in [:ok, :not_configured]
 
     if all_healthy do
@@ -46,16 +51,23 @@ defmodule ToweropsWeb.HealthController do
   end
 
   defp check_redis do
+    require Logger
+
     redis_config = Application.get_env(:towerops, :redis, [])
 
     if Keyword.has_key?(redis_config, :host) do
       # Redis is configured, check connectivity with short timeout for health check
       case Towerops.RedisHealthCheck.check_health(redis_config, 2_000) do
-        :ok -> :ok
-        {:error, _} -> :error
+        :ok ->
+          :ok
+
+        {:error, reason} ->
+          Logger.error("Redis health check failed: #{inspect(reason)}")
+          :error
       end
     else
       # Redis not configured (e.g., in development without Redis)
+      Logger.debug("Redis not configured")
       :not_configured
     end
   end