New KreaPaletteToPromptText node converts an extracted hex palette into
a natural-language color clause via nearest-name lookup against a fixed
table (utils/color_names.py) -- pure local color math, no API calls.
This makes the credit-free path fully automated end to end (reference
image -> palette -> ready-to-paste prompt clause), instead of requiring
manual color naming.
Adds showcase_04_free_local_prompt_text.json demonstrating the fully
free pipeline, and restructures the README so the free local path is
the primary documented flow, with Krea's paid cloud Style Reference /
Image Partner Nodes clearly marked as an optional branch.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
