Instrument code suggetions auth events to product analytics

config/events/code_suggestions_authenticate.yml

+---
+description: Tracks the number of authentication requests to the `POST /code_suggestions/tokens` API endpoint.
+category: InternalEventTracking
+action: code_suggestions_authenticate
+label_description:
+property_description:
+value_description:
+extra_properties:
+identifiers:
+- user
+product_section: dev
+product_stage: create
+product_group: code_creation
+milestone: "16.7"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138848
+distributions:
+- ce
+- ee
+tiers:
+- free
+- premium
+- ultimate

config/metrics/counts_28d/count_total_code_suggestions_authenticate_28d.yml

+---
+key_path: count_total_code_suggestions_authenticate_28d
+description: Tracks the number of authentication requests to the `POST /code_suggestions/tokens` API endpoint in the last 28 days.
+product_section: dev
+product_stage: create
+product_group: code_creation
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: "16.7"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138848
+time_frame: 28d
+data_source: internal_events
+data_category: optional
+instrumentation_class: TotalCountMetric
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+options:
+  events:
+    - code_suggestions_authenticate
+events:
+  - name: code_suggestions_authenticate

config/metrics/counts_7d/count_total_code_suggestions_authenticate_7d.yml

+---
+key_path: count_total_code_suggestions_authenticate_7d
+description: Tracks the number of authentication requests to the `POST /code_suggestions/tokens` API endpoint in the last 7 days.
+product_section: dev
+product_stage: create
+product_group: code_creation
+performance_indicator_type: []
+value_type: number
+status: active
+milestone: "16.7"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138848
+time_frame: 7d
+data_source: internal_events
+data_category: optional
+instrumentation_class: TotalCountMetric
+distribution:
+- ce
+- ee
+tier:
+- free
+- premium
+- ultimate
+options:
+  events:
+    - code_suggestions_authenticate
+events:
+  - name: code_suggestions_authenticate

ee/lib/api/code_suggestions.rb

@@ -101,6 +101,11 @@ def gitlab_realm
             label: 'code_suggestions'
           )
 
+          Gitlab::InternalEvents.track_event(
+            'code_suggestions_authenticate',
+            user: current_user
+          )
+
           token = Gitlab::Ai::AccessToken.new(current_user, scopes: [:code_suggestions], gitlab_realm: gitlab_realm)
           present token, with: Entities::CodeSuggestionsAccessToken
         end