feat: Enhance holding detail drawer with live price sync and enriched overview (#1086)

* Feat: Implement manual sync prices functionality and enhance holdings display

* Feat: Enhance sync prices functionality with error handling and update UI components

* Feat: Update sync prices error handling and enhance Spanish locale messages

* Fix: Address CodeRabbit review feedback

- Set fallback @provider_error when prices_updated == 0 so turbo stream
  never fails silently without a visible error message
- Move attr_reader :provider_error to class header in Price::Importer
  for conventional placement alongside other attribute declarations
- Precompute @last_price_updated in controller (show + sync_prices)
  instead of running a DB query directly inside ERB templates

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

* Fix: Replace bare rescue with explicit exception handling in turbo stream view

Bare `rescue` silently swallows all exceptions, making debugging impossible.
Match the pattern already used in show.html.erb: rescue ActiveRecord::RecordInvalid
explicitly, then catch StandardError with logging (message + backtrace) before
falling back to the unknown label.

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

* Fix: Update test assertion to expect actual provider error message

The stub returns "Yahoo Finance rate limit exceeded" as the provider error.
After the @provider_error fallback fix, the controller now correctly surfaces
the real provider error when present (using .presence || fallback), so the
flash[:alert] is the actual error string, not the generic fallback.

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

* Fix: Assert scoped security_ids in sync_prices materializer test

Replace loose stub with constructor expectation to verify that
Balance::Materializer is instantiated with the single-security scope.

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

* Fix: Assert holding remap in remap_security test

Add assertion that @holding.security_id is updated to the target
security after remap, covering the core command outcome.

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

* Fix: CI test failure - Update disconnect external assistant test to use env overrides

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

test/controllers/settings/hostings_controller_test.rb

@@ -201,16 +201,18 @@ class Settings::HostingsControllerTest < ActionDispatch::IntegrationTest
 
   test "disconnect external assistant clears settings and resets type" do
     with_self_hosting do
-      Setting.external_assistant_url = "https://agent.example.com/v1/chat"
-      Setting.external_assistant_token = "token"
-      Setting.external_assistant_agent_id = "finance-bot"
-      users(:family_admin).family.update!(assistant_type: "external")
+      with_env_overrides("EXTERNAL_ASSISTANT_URL" => nil, "EXTERNAL_ASSISTANT_TOKEN" => nil) do
+        Setting.external_assistant_url = "https://agent.example.com/v1/chat"
+        Setting.external_assistant_token = "token"
+        Setting.external_assistant_agent_id = "finance-bot"
+        users(:family_admin).family.update!(assistant_type: "external")
 
-      delete disconnect_external_assistant_settings_hosting_url
+        delete disconnect_external_assistant_settings_hosting_url
 
-      assert_redirected_to settings_hosting_url
-      assert_not Assistant::External.configured?
-      assert_equal "builtin", users(:family_admin).family.reload.assistant_type
+        assert_redirected_to settings_hosting_url
+        assert_not Assistant::External.configured?
+        assert_equal "builtin", users(:family_admin).family.reload.assistant_type
+      end
     end
   ensure
     Setting.external_assistant_url = nil