CTk Theme Builder 3.2.x

This release focuses on packaging readiness, developer workflow improvements, and a round of UI and theme refinements.

What's new

Added Poetry-based packaging and release preparation.
Improved PyPI readiness with updated project metadata, README polish, and more reliable test bootstrapping.
Added an icon browser.
Added a runtime log viewer.
Improved preview-panel startup and handshake reliability.
Refined asset migration behaviour during upgrades/startup.
Added the new Phoenix theme.
Applied colour refinements to:
- Anthracite
- Cobalt
- DaynNight
- GhostTrain
- Greengage
- GreyGhost
- Hades
- Harlequin
- TrojanBlue

Added/updated release helper scripts, including wheel install testing and publishing support.
Modernised launcher, interpreter, and virtual-environment handling.
Updated installation, upgrade, and user documentation.
Added or refreshed tests around preferences and utility behaviour.

This release continues the move towards a cleaner ctk_tb package structure.
The main emphasis has been on making the application easier to package, test, release, and maintain.