Add Coinbase exchange integration with CDP API support (#704)

* **Add Coinbase integration with item and account management**
- Creates migrations for `coinbase_items` and `coinbase_accounts`.
- Adds models, controllers, views, and background tasks to support account linking, syncing, and transaction handling.
- Implements Coinbase API client and adapter for seamless integration.
- Supports ActiveRecord encryption for secure credential storage.
- Adds UI components for provider setup, account management, and synchronization.

* Localize Coinbase-related UI strings, refine account linking for security, and add timeouts to Coinbase API requests.

* Localize Coinbase account handling to support native currencies (USD, EUR, GBP, etc.) across balances, trades, holdings, and transactions.

* Improve Coinbase processing with timezone-safe parsing, native currency support, and immediate holdings updates.

* Improve trend percentage formatting and enhance race condition handling for Coinbase account linking.

* Fix log message wording for orphan cleanup

* Ensure `selected_accounts` parameter is sanitized by rejecting blank entries.

* Add tests for Coinbase integration: account, item, and controller coverage

- Adds unit tests for `CoinbaseAccount` and `CoinbaseItem` models.
- Adds integration tests for `CoinbaseItemsController`.
- Introduces Stimulus `select-all` controller for UI checkbox handling.
- Localizes UI strings and logging for Coinbase integration.

* Update test fixtures to use consistent placeholder API keys and secrets

* Refine `coinbase_item` tests to ensure deterministic ordering and improve scope assertions.

* Integrate `SyncStats::Collector` into Coinbase syncer to streamline statistics collection and enhance consistency.

* Localize Coinbase sync status messages and improve sync summary test coverage.

* Update `CoinbaseItem` encryption: use deterministic encryption for `api_key` and standard for `api_secret`.

* fix schema drift

* Beta labels to lower expectations

---------

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

Gemfile.lock

@@ -180,6 +180,7 @@ GEM
       dotenv (= 3.1.8)
       railties (>= 6.1)
     drb (2.2.3)
+    ed25519 (1.4.0)
     email_validator (2.2.4)
       activemodel
     erb (5.0.1)
@@ -778,6 +779,7 @@ DEPENDENCIES
   derailed_benchmarks
   doorkeeper
   dotenv-rails
+  ed25519
   erb_lint
   faker
   faraday