Requests can be tagged: metadata, x-llmgw-tags and the user field on the usage record, and counted by the tags router.tag_labels names

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/control/adminapi/api.go

@@ -1406,6 +1406,9 @@ type RequestView struct {
 	GuardPolicy   string `json:"guard_policy,omitempty"`
 	GuardCategory string `json:"guard_category,omitempty"`
 	GuardMs       int64  `json:"guard_ms,omitempty"`
+	// What the client said about it: OpenAI's user field, and its tags.
+	EndUser string            `json:"end_user,omitempty"`
+	Tags    map[string]string `json:"tags,omitempty"`
 }
 
 func (a *API) request(w http.ResponseWriter, r *http.Request) {
@@ -1429,6 +1432,7 @@ func (a *API) request(w http.ResponseWriter, r *http.Request) {
 		LatencyMs: u.LatencyMs, QueueMs: u.QueueMs, TTFTMs: u.TTFTMs,
 		PromptTokens: u.PromptTokens, CompletionTokens: u.CompletionTokens, CostMicros: u.CostMicros,
 		GuardAction: u.GuardAction, GuardPolicy: u.GuardPolicy, GuardCategory: u.GuardCategory, GuardMs: u.GuardMs,
+		EndUser: u.EndUser, Tags: u.Tags,
 	})
 }