Pending detection, FX metadata, Pending UI badge. (#374)

* - Add support for `SIMPLEFIN_INCLUDE_PENDING` to control pending behavior via ENV.
- Enhance debug logging for SimpleFin API requests and raw payloads.
- Refine pending flag handling in `SimplefinEntry::Processor` based on provider data and inferred conditions.
- Improve FX metadata processing for transactions with currency mismatches.
- Add new tests for pending detection, FX metadata, and edge cases involving `posted` values.
- Add pending indicator UI to transaction view.

* Document pending transaction detection, storage, and UI behavior for SimpleFIN and Plaid integrations. Add debug flags for troubleshooting.

* Add `pending?` method to `Transaction` model, refactor UI indicator, and centralize SimpleFIN configuration

- Introduced `pending?` method in `Transaction` for unified pending state detection.
- Refactored transaction pending indicator in the UI to use `pending?` method.
- Centralized SimpleFIN configuration in initializer with ENV-backed toggles.
- Updated tests for `pending?` behavior and clarified docs for pending detection logic

* Add SimpleFIN debug and runtime flags to `.env.local.example` and `.env.test.example`

- Introduced `SIMPLEFIN_INCLUDE_PENDING` and `SIMPLEFIN_DEBUG_RAW` flags for controlling pending behavior and debugging.
- Updated example environment files with descriptions for new configuration options.

* Normalize formatting for `SIMPLEFIN_INCLUDE_PENDING` and `SIMPLEFIN_DEBUG_RAW` flags in `.env.local.example` and `.env.test.example`.

---------

Co-authored-by: Josh Waldrep <joshua.waldrep5+github@gmail.com>

app/models/transaction.rb

@@ -31,4 +31,12 @@ class Transaction < ApplicationRecord
 
     update!(category: category)
   end
+
+  def pending?
+    extra_data = extra.is_a?(Hash) ? extra : {}
+    ActiveModel::Type::Boolean.new.cast(extra_data.dig("simplefin", "pending")) ||
+      ActiveModel::Type::Boolean.new.cast(extra_data.dig("plaid", "pending"))
+  rescue
+    false
+  end
 end