Add comprehensive API v1 with OAuth and API key authentication (#2389)

* OAuth

* Add API test routes and update Doorkeeper token handling for test environment

- Introduced API namespace with test routes for controller testing in the test environment.
- Updated Doorkeeper configuration to allow fallback to plain tokens in the test environment for easier testing.
- Modified schema to change resource_owner_id type from bigint to string.

* Implement API key authentication and enhance access control

- Replaced Doorkeeper OAuth authentication with a custom method supporting both OAuth and API keys in the BaseController.
- Added methods for API key authentication, including validation and logging.
- Introduced scope-based authorization for API keys in the TestController.
- Updated routes to include API key management endpoints.
- Enhanced logging for API access to include authentication method details.
- Added tests for API key functionality, including validation, scope checks, and access control enforcement.

* Add API key rate limiting and usage tracking

- Implemented rate limiting for API key authentication in BaseController.
- Added methods to check rate limits, render appropriate responses, and include rate limit headers in responses.
- Updated routes to include a new usage resource for tracking API usage.
- Enhanced tests to verify rate limit functionality, including exceeding limits and per-key tracking.
- Cleaned up Redis data in tests to ensure isolation between test cases.

* Add Jbuilder for JSON rendering and refactor AccountsController

- Added Jbuilder gem for improved JSON response handling.
- Refactored index action in AccountsController to utilize Jbuilder for rendering JSON.
- Removed manual serialization of accounts and streamlined response structure.
- Implemented a before_action in BaseController to enforce JSON format for all API requests.

* Add transactions resource to API routes

- Added routes for transactions, allowing index, show, create, update, and destroy actions.
- This enhancement supports comprehensive transaction management within the API.

* Enhance API authentication and onboarding handling

- Updated BaseController to skip onboarding requirements for API endpoints and added manual token verification for OAuth authentication.
- Improved error handling and logging for invalid access tokens.
- Introduced a method to set up the current context for API requests, ensuring compatibility with session-like behavior.
- Excluded API paths from onboarding redirects in the Onboardable concern.
- Updated database schema to change resource_owner_id type from bigint to string for OAuth access grants.

* Fix rubocop offenses

- Fix indentation and spacing issues
- Convert single quotes to double quotes
- Add spaces inside array brackets
- Fix comment alignment
- Add missing trailing newlines
- Correct else/end alignment

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* Fix API test failures and improve test reliability

- Fix ApiRateLimiterTest by removing mock users method and using fixtures
- Fix UsageControllerTest by removing mock users method and using fixtures
- Fix BaseControllerTest by using different users for multiple API keys
- Use unique display_key values with SecureRandom to avoid conflicts
- Fix double render issue in UsageController by returning after authorize_scope\!
- Specify controller name in routes for usage resource
- Remove trailing whitespace and empty lines per Rubocop

All tests now pass and linting is clean.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* Add API transactions controller warning to brakeman ignore

The account_id parameter in the API transactions controller is properly
validated on line 79: family.accounts.find(transaction_params[:account_id])
This ensures users can only create transactions in accounts belonging to
their family, making this a false positive.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

---------

Signed-off-by: Josh Pigford <josh@joshpigford.com>
Co-authored-by: Claude <noreply@anthropic.com>

config/routes.rb

@@ -2,6 +2,7 @@ require "sidekiq/web"
 require "sidekiq/cron/web"
 
 Rails.application.routes.draw do
+  use_doorkeeper
   # MFA routes
   resource :mfa, controller: "mfa", only: [ :new, :create ] do
     get :verify
@@ -55,6 +56,7 @@ Rails.application.routes.draw do
     end
     resource :billing, only: :show
     resource :security, only: :show
+    resource :api_key, only: [ :show, :new, :create, :destroy ]
   end
 
   resource :subscription, only: %i[new show create] do
@@ -180,6 +182,27 @@ Rails.application.routes.draw do
     get :accept, on: :member
   end
 
+  # API routes
+  namespace :api do
+    namespace :v1 do
+      # Production API endpoints
+      resources :accounts, only: [ :index ]
+      resources :transactions, only: [ :index, :show, :create, :update, :destroy ]
+      resource :usage, only: [ :show ], controller: "usage"
+
+      # Test routes for API controller testing (only available in test environment)
+      if Rails.env.test?
+        get "test", to: "test#index"
+        get "test_not_found", to: "test#not_found"
+        get "test_family_access", to: "test#family_access"
+        get "test_scope_required", to: "test#scope_required"
+        get "test_multiple_scopes_required", to: "test#multiple_scopes_required"
+      end
+    end
+  end
+
+
+
   resources :currencies, only: %i[show]
 
   resources :impersonation_sessions, only: [ :create ] do