Add SnapTrade brokerage integration with full trade history support (#737)

* Introduce SnapTrade integration with models, migrations, views, and activity processing logic.

* Refactor SnapTrade activities processing: improve activity fetching flow, handle pending states, and update UI elements for enhanced user feedback.

* Update Brakeman ignore file to include intentional redirect for SnapTrade OAuth portal.

* Refactor SnapTrade models, views, and processing logic: add currency extraction helper, improve pending state handling, optimize migration checks, and enhance user feedback in UI.

* Remove encryption for SnapTrade `snaptrade_user_id`, as it is an identifier, not a secret.

* Introduce `SnaptradeConnectionCleanupJob` to asynchronously handle SnapTrade connection cleanup and improve i18n for SnapTrade item status messages.

* Update SnapTrade encryption: make `snaptrade_user_secret` non-deterministic to enhance security.

---------

Signed-off-by: Juan José Mata <juanjo.mata@gmail.com>
Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>
Co-authored-by: Juan José Mata <juanjo.mata@gmail.com>

app/components/provider_sync_summary.rb

@@ -19,15 +19,21 @@
 #   ) %>
 #
 class ProviderSyncSummary < ViewComponent::Base
-  attr_reader :stats, :provider_item, :institutions_count
+  attr_reader :stats, :provider_item, :institutions_count, :activities_pending
 
   # @param stats [Hash] The sync statistics hash from sync.sync_stats
   # @param provider_item [Object] The provider item (must respond to last_synced_at)
   # @param institutions_count [Integer, nil] Optional count of connected institutions
-  def initialize(stats:, provider_item:, institutions_count: nil)
+  # @param activities_pending [Boolean] Whether activities are still being fetched in background
+  def initialize(stats:, provider_item:, institutions_count: nil, activities_pending: false)
     @stats = stats || {}
     @provider_item = provider_item
     @institutions_count = institutions_count
+    @activities_pending = activities_pending
+  end
+
+  def activities_pending?
+    @activities_pending
   end
 
   def render?
@@ -102,6 +108,19 @@ class ProviderSyncSummary < ViewComponent::Base
     stats.key?("holdings_processed") ? holdings_processed : holdings_found
   end
 
+  # Trades statistics (investment activities like buy/sell)
+  def trades_imported
+    stats["trades_imported"].to_i
+  end
+
+  def trades_skipped
+    stats["trades_skipped"].to_i
+  end
+
+  def has_trades_stats?
+    stats.key?("trades_imported") || stats.key?("trades_skipped")
+  end
+
   # Returns the CSS color class for a data quality detail severity
   # @param severity [String] The severity level ("warning", "error", or other)
   # @return [String] The Tailwind CSS class for the color