Data provider simplification, tests, and documentation (#1997)

* Ignore env.test from source control

* Simplification of providers interface

* Synth tests

* Update money to use new find rates method

* Remove unused issues code

* Additional issue feature removals

* Update price data fetching and tests

* Update documentation for providers

* Security test fixes

* Fix self host test

* Update synth usage data access

* Remove AI pr schema changes

app/models/provider.rb

@@ -0,0 +1,35 @@
+class Provider
+  include Retryable
+
+  ProviderError = Class.new(StandardError)
+  ProviderResponse = Data.define(:success?, :data, :error)
+
+  private
+    PaginatedData = Data.define(:paginated, :first_page, :total_pages)
+    UsageData = Data.define(:used, :limit, :utilization, :plan)
+
+    # Subclasses can specify errors that can be retried
+    def retryable_errors
+      []
+    end
+
+    def provider_response(retries: nil, &block)
+      data = if retries
+        retrying(retryable_errors, max_retries: retries) { yield }
+      else
+        yield
+      end
+
+      ProviderResponse.new(
+        success?: true,
+        data: data,
+        error: nil,
+      )
+    rescue StandardError => error
+      ProviderResponse.new(
+        success?: false,
+        data: nil,
+        error: error,
+      )
+    end
+end