fix: remove unreachable error clauses causing compile warnings

Fixed three compile warnings by removing unreachable error handling:

1. Dynamic.discover_sensors/2 always returns {:ok, sensors}, never errors
   - Removed unreachable error clause in discovery.ex
   - Updated spec to reflect actual return type

2. parse_detection_rule/2 always returns {:ok, :processed}
   - Simplified create_detection_rules/2 to use Enum.each instead of reduce_while
   - Removed unreachable error handling in caller

3. import_all_from_directory/2 always returns {:ok, %{...}}
   - Removed unreachable error clause in Mix task
   - Simplified to direct pattern match

All code now compiles without warnings.

lib/mix/tasks/import_profiles.ex

@@ -122,15 +122,10 @@ defmodule Mix.Tasks.ImportProfiles do
       Mix.shell().info("Importing all profiles from: #{librenms_path}")
       Mix.shell().info("This may take several minutes...")
 
-      case Importer.import_all_from_directory(detection_dir, discovery_dir) do
-        {:ok, stats} ->
-          Mix.shell().info("\nImport complete!")
-          Mix.shell().info("Successfully imported: #{stats.success} profiles")
-          Mix.shell().info("Failed to import: #{stats.failed} profiles")
-
-        {:error, reason} ->
-          Mix.shell().error("Failed to import profiles: #{inspect(reason)}")
-      end
+      {:ok, stats} = Importer.import_all_from_directory(detection_dir, discovery_dir)
+      Mix.shell().info("\nImport complete!")
+      Mix.shell().info("Successfully imported: #{stats.success} profiles")
+      Mix.shell().info("Failed to import: #{stats.failed} profiles")
     else
       Mix.shell().error("external path not found. Use --librenms-path option.")
     end

lib/towerops/device_profiles/importer.ex

@@ -97,10 +97,8 @@ defmodule Towerops.DeviceProfiles.Importer do
     case DeviceProfiles.create_profile(attrs) do
       {:ok, profile} ->
         # Create detection rules
-        case create_detection_rules(profile.id, data["discovery"] || []) do
-          :ok -> {:ok, profile}
-          {:error, _} = error -> error
-        end
+        :ok = create_detection_rules(profile.id, data["discovery"] || [])
+        {:ok, profile}
 
       {:error, _} = error ->
         error
@@ -108,12 +106,11 @@ defmodule Towerops.DeviceProfiles.Importer do
   end
 
   defp create_detection_rules(profile_id, rules) when is_list(rules) do
-    Enum.reduce_while(rules, :ok, fn rule, _acc ->
-      case parse_detection_rule(profile_id, rule) do
-        {:ok, _} -> {:cont, :ok}
-        {:error, _} = error -> {:halt, error}
-      end
+    Enum.each(rules, fn rule ->
+      parse_detection_rule(profile_id, rule)
     end)
+
+    :ok
   end
 
   defp parse_detection_rule(profile_id, rule) do

lib/towerops/snmp/discovery.ex

@@ -301,15 +301,9 @@ defmodule Towerops.Snmp.Discovery do
 
   @spec discover_sensors(Client.connection_opts(), profile()) :: {:ok, [sensor_data()]}
   defp discover_sensors(client_opts, {:dynamic, profile}) do
-    case Dynamic.discover_sensors(profile, client_opts) do
-      {:ok, sensors} ->
-        Logger.debug("Discovered #{length(sensors)} sensors")
-        {:ok, sensors}
-
-      {:error, _} ->
-        Logger.warning("Sensor discovery failed, continuing without sensors")
-        {:ok, []}
-    end
+    {:ok, sensors} = Dynamic.discover_sensors(profile, client_opts)
+    Logger.debug("Discovered #{length(sensors)} sensors")
+    {:ok, sensors}
   end
 
   defp discover_sensors(client_opts, profile) when is_atom(profile) do

lib/towerops/snmp/profiles/dynamic.ex

@@ -54,7 +54,7 @@ defmodule Towerops.Snmp.Profiles.Dynamic do
   Walks SNMP OIDs defined in the profile's sensor_definitions.
   """
   @spec discover_sensors(DeviceProfile.t(), Client.connection_opts()) ::
-          {:ok, [Discovery.sensor_data()]} | {:error, term()}
+          {:ok, [Discovery.sensor_data()]}
   def discover_sensors(profile, client_opts) do
     # Load profile with sensor definitions
     profile = DeviceProfiles.get_profile_with_associations(profile.os)