Address code review findings across relay, UI, and Go backend

- relay: key uploadables map by actual variable name instead of iteration
  index so order-mismatch between Object.keys passes can't desync the
  multipart map from form field names
- mcp/v1: drop dead commented middleware line
- DurationPicker: tighten parse regex to require PT prefix for M/H and P
  for D/W, and reject NaN in stringify so cleared inputs don't produce
  invalid duration strings

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

pkg/server/api/mcp/v1/v1_handler.go

@@ -40,7 +40,6 @@ func NewMux(logger *log.Logger, proboSvc *probo.Service, iamSvc *iam.Service, ac
 	logger = logger.Named("mcp.v1")
 
 	logger.Info("initializing MCP server")
-	// server.AddReceivingMiddleware(mcputils.LoggingMiddleware(logger))
 
 	resolver := &Resolver{
 		proboSvc:     proboSvc,