refactor: consolidate settings lookups and secrets loading

- Extract fetch_setting/1 in Settings (4 callsites → 1 repo lookup)
- Replace hardcoded load_stripe_config with registry-driven load_all
- Adding new secrets is now a one-line @secret_registry entry
- Mark DRY refactor plan as complete (all 8 items done)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/simpleshop_theme/secrets.ex

@@ -13,30 +13,27 @@ defmodule SimpleshopTheme.Secrets do
 
   require Logger
 
+  # Registry of {settings_key, app, env_key} — add new secrets here
+  @secret_registry [
+    {"stripe_api_key", :stripity_stripe, :api_key},
+    {"stripe_signing_secret", :stripity_stripe, :signing_secret}
+  ]
+
   @doc """
   Loads all secrets from the database into Application env.
 
   Called at startup from the supervision tree, after the Repo is ready.
   """
   def load_all do
-    load_stripe_config()
-  end
+    for {settings_key, app, env_key} <- @secret_registry do
+      case Settings.get_secret(settings_key) do
+        nil ->
+          :skip
 
-  @doc """
-  Loads Stripe credentials from encrypted settings into Application env.
-  """
-  def load_stripe_config do
-    api_key = Settings.get_secret("stripe_api_key")
-    signing_secret = Settings.get_secret("stripe_signing_secret")
-
-    if api_key do
-      Application.put_env(:stripity_stripe, :api_key, api_key)
-      Logger.debug("Stripe API key loaded from database")
-    end
-
-    if signing_secret do
-      Application.put_env(:stripity_stripe, :signing_secret, signing_secret)
-      Logger.debug("Stripe webhook secret loaded from database")
+        value ->
+          Application.put_env(app, env_key, value)
+          Logger.debug("Loaded #{settings_key} from database")
+      end
     end
 
     :ok

lib/simpleshop_theme/settings.ex

@@ -18,9 +18,9 @@ defmodule SimpleshopTheme.Settings do
 
   """
   def get_setting(key, default \\ nil) do
-    case Repo.get_by(Setting, key: key) do
-      nil -> default
-      setting -> decode_value(setting)
+    case fetch_setting(key) do
+      {:ok, setting} -> decode_value(setting)
+      :not_found -> default
     end
   end
 
@@ -120,9 +120,9 @@ defmodule SimpleshopTheme.Settings do
   Deletes a setting by key.
   """
   def delete_setting(key) do
-    case Repo.get_by(Setting, key: key) do
-      nil -> :ok
-      setting -> Repo.delete(setting)
+    case fetch_setting(key) do
+      {:ok, setting} -> Repo.delete(setting)
+      :not_found -> :ok
     end
   end
 
@@ -157,8 +157,9 @@ defmodule SimpleshopTheme.Settings do
   Returns the plaintext value or the default if not found.
   """
   def get_secret(key, default \\ nil) do
-    case Repo.get_by(Setting, key: key) do
-      %Setting{value_type: "encrypted", encrypted_value: encrypted} when not is_nil(encrypted) ->
+    case fetch_setting(key) do
+      {:ok, %Setting{value_type: "encrypted", encrypted_value: encrypted}}
+      when not is_nil(encrypted) ->
         case Vault.decrypt(encrypted) do
           {:ok, plaintext} -> plaintext
           {:error, _} -> default
@@ -173,8 +174,9 @@ defmodule SimpleshopTheme.Settings do
   Checks whether an encrypted secret exists in the database.
   """
   def has_secret?(key) do
-    case Repo.get_by(Setting, key: key) do
-      %Setting{value_type: "encrypted", encrypted_value: encrypted} when not is_nil(encrypted) ->
+    case fetch_setting(key) do
+      {:ok, %Setting{value_type: "encrypted", encrypted_value: encrypted}}
+      when not is_nil(encrypted) ->
         true
 
       _ ->
@@ -204,6 +206,13 @@ defmodule SimpleshopTheme.Settings do
 
   # Private helpers
 
+  defp fetch_setting(key) do
+    case Repo.get_by(Setting, key: key) do
+      nil -> :not_found
+      setting -> {:ok, setting}
+    end
+  end
+
   defp decode_value(%Setting{value_type: "encrypted", encrypted_value: encrypted})
        when not is_nil(encrypted) do
     case Vault.decrypt(encrypted) do

lib/simpleshop_theme/stripe/setup.ex

@@ -36,13 +36,13 @@ defmodule SimpleshopTheme.Stripe.Setup do
 
       case maybe_create_webhook(api_key) do
         {:ok, result} ->
-          Secrets.load_stripe_config()
+          Secrets.load_all()
           {:ok, result}
 
         {:error, reason} ->
           # Key is valid and stored, but webhook creation failed.
           # Still load the key so checkout works (webhooks can be set up manually).
-          Secrets.load_stripe_config()
+          Secrets.load_all()
           {:error, reason}
       end
     end
@@ -68,7 +68,7 @@ defmodule SimpleshopTheme.Stripe.Setup do
   """
   def save_signing_secret(signing_secret) do
     Settings.put_secret("stripe_signing_secret", signing_secret)
-    Secrets.load_stripe_config()
+    Secrets.load_all()
   end
 
   @doc """