[Bug]: Root project: relational database connection visibility and rename issues

### Apache Hop version?

2.14.0

### Java version?

1.8.0

### Operating system

Windows

### What happened?

There are several issues related to relational database connections defined **in the root project:**
**Visibility in sub-projects**
Normally, a relational database connection created in the root project should be visible to sub-projects.
However, if a connection with the same name already exists in the sub-project, the root connection is not visible there.
As soon as you **rename** the connection in the root, it becomes visible again in the sub-project.
**Name-based linkage**
Workflows and pipelines reference database connections by **name**, not by path.
This means:
If you **rename** a connection, all workflows/pipelines that used it will break and you have to manually reselect the connection everywhere.
If you only **move** the connection (without renaming), workflows/pipelines continue to work correctly, since they link by name only.
**Case-sensitivity issue when renaming**
If you try to rename a connection only by changing the case (e.g. Test → test), Hop reports **“already exists”.**
Workaround: you have to rename to a different name first (e.g. Test → Mest → test).
**Steps to Reproduce**
Create a relational database connection in the root project (e.g. Test).
In a sub-project, check if the root connection is visible.
If a local connection with the same name exists, the root one is hidden.
Rename the root connection.
It immediately becomes visible in the sub-project.
Use the connection in a workflow.
**Rename the connection** → the workflow loses the reference.
**Move the connection without renaming** → the workflow still works.
Try renaming Test → test.
Error: “already exists”.
Workaround: Test → Mest → test.

### Issue Priority

Priority: 3

### Issue Component

Component: Hop Gui

Start in the Hop GUI by reproducing the root-project and sub-project visibility cases, then test renaming and moving a connection used by a workflow. Done means root connections remain visible when names collide, workflow references survive renames, and case-only renames succeed without the “already exists” error.

Written by the indexing model from the issue text.