[dnltz]

Supersedes #41 by @Gerard-Taulats with the open review feedback addressed and a
cleaned up history. The commits keep his authorship.

The hardcoded PDK table is gone: every layer stack config in
import_gdsii/configs is offered as a preset, so users can add their own PDK by
dropping a config file next to the shipped ones together with a color schema
directory of the same name. The list is read once and refreshed whenever the
import dialog opens, so a new config shows up without restarting Blender.

A config file may describe itself in an optional pdk_config section (name,
description, def_color); everything falls back to the file name. The preset
order lives in configs/_config_order.yaml, so it no longer has to be
maintained across several files. Configs missing from that list are appended in
alphabetical order instead of being dropped.

Changes on top of #41:

• Order entries are matched against the PDK keys again — the list was silently
  ignored before, and the _ placeholder is replaced by the fallback above
• Two f"...{d["key"]}..." fallbacks that are a SyntaxError before Python
  3.12 are gone; the config and color paths now come straight from the loaded
  config, and an unknown PDK is reported instead of raising
• pdk_config is dropped from the layer stack after loading instead of being
  skipped in every consumer
• Malformed or empty YAML files in the config directory are ignored with a
  warning instead of breaking the add-on
• _config_order.yaml entries without a config file now fail the config check
• Debug print, stale IHP_SG13G2 fallbacks, the unused order schema field and
  the whitespace noise are removed

Note: the SiEPIC preset identifier changes from SIEPIC_EBEAM to SIEPIC,
since identifiers are derived from the config file name (siepic.yaml).

Tested with Blender 4.3.2: importing with a built-in PDK, with a custom config
and color schema, and with an unknown PDK stored in the scene, plus tox on
every commit.

[dnltz]

@Gerard-Taulats I addressed all the feedback from #41 and cleaned up the history. You're still the Author of this commits! Do you see any issue with those patches here?

[Gerard-Taulats]

I'm so sorry it took me this long to get back to this. So long, you were about to take care of the rest yourself😅. I'll take a look now

[Gerard-Taulats]

I reviewed the code and tested. Works like a charm👌

[dnltz]

I reviewed the code and tested. Works like a charm👌

thanks for testing. I also ran some and it fixed one bug on Metal1. Now worries with not reacting. You almost provided everything and I just had to clean it up :)