LCInterlocking Extended

### 🔌 𝗥𝗲𝗽𝗼𝘀𝗶𝘁𝗼𝗿𝘆

https://github.com/grandcedrebleu/LCInterlocking-Extended

### 📑 𝗡𝗼𝘁𝗲𝘀

```txt
LCInterlocking Extended is a maintained fork of LCInterlocking,
currently based on upstream LCInterlocking 1.5.1.

It adds a configurable through-cut margin to the boolean cutting
tools used for interlocking joints.

This addresses residual thin faces ("skins") that can remain at
the bottom of slots when the cutting solid terminates exactly on
the opposite face, due to geometric/boolean tolerances.

The default margin is 0.10 mm per side and can be changed by the
user in the MultiJoin parameters.

Version 1.1.0 also isolates the Python modules and FreeCAD command
identifiers used by the fork. LCInterlocking Extended can therefore
be installed and used alongside the original LCInterlocking
workbench without module or command-name collisions.

Tested successfully with:
- FreeCAD 1.1.1
- FreeCAD 1.1.3

On FreeCAD 1.1.3, the original LCInterlocking and LCInterlocking
Extended were installed simultaneously and both workbenches were
successfully loaded and used.

The addon has also been successfully installed and updated through
FreeCAD's Addon Manager using the dist branch as a custom repository.

Upstream project:
execuc/LCInterlocking

License:
LGPL-2.1-or-later
```

Start by reviewing the Addons repository's index structure and the linked LCInterlocking Extended repository, including its Addon Manager installation details. Done means the addon is represented in the appropriate index location with the available repository and compatibility information.

Written by the indexing model from the issue text.