Subgraph IO order can drift between inner pins, outer pins, and properties panel

## Problem
Subgraph input/output order can drift between:
- the IO pins shown inside subgraph editing mode
- the pins shown on the outer subgraph node
- the order shown in the properties / right-side panel

These views should all reflect the same canonical subgraph IO order, but in practice they can get out of sync after load/configure cycles or other subgraph updates.

## Expected behavior
There should be a single source of truth for subgraph input/output order, and every representation should follow it consistently:
- inner subgraph IO rows
- outer subgraph node pins
- properties panel order
- promoted subgraph widget order

## Actual behavior
The order can change or drift so that the inside view and outside view no longer match, which makes editing subgraphs frustrating and error-prone.

## Why this matters
This is not just a visual polish issue. When the order differs between views, it becomes harder to reason about what is actually exposed by the subgraph and in what order, especially when promoting widgets or revisiting saved workflows.

## Notes
I’m filing this as a frontend issue because the mismatch appears to be in how subgraph IO order is reconstructed/rendered across frontend views rather than in the intended product behavior.

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-10221-Subgraph-IO-order-can-drift-between-inner-pins-outer-pins-and-properties-panel-3266d73d3650815db43cf3f5cb7772c7) by [Unito](https://www.unito.io)