feat(redis): implement Pub/Sub support for usage tracking

- Added Redis Pub/Sub capability to broadcast usage updates to subscribed clients.
- Enhanced `redisqueue` with subscriber management and message broadcasting.
- Updated tests to validate Pub/Sub message handling, subscription behavior, and fallback to the queue after unsubscribing.
- Integrated `project_id` parsing into auth-files logic to include project identifiers in metadata.

Closes: #3027

internal/api/handlers/management/auth_files.go

@@ -1919,7 +1919,7 @@ func (h *Handler) RequestCodexToken(c *gin.Context) {
 		bundle, errExchange := openaiAuth.ExchangeCodeForTokens(ctx, code, pkceCodes)
 		if errExchange != nil {
 			authErr := codex.NewAuthenticationError(codex.ErrCodeExchangeFailed, errExchange)
-			SetOAuthSessionError(state, "Failed to exchange authorization code for tokens")
+			SetOAuthSessionError(state, oauthSessionErrorWithCause("Failed to exchange authorization code for tokens", errExchange))
 			log.Errorf("Failed to exchange authorization code for tokens: %v", authErr)
 			return
 		}