Initial commit: UTFCN — Use The (F***ing) Core Nodes

A ComfyUI companion that suggests core / available equivalents for custom
nodes and replaces them in a workflow.

- Backend (utfcn_core.py, __init__.py): read-only /utfcn/scan analysis that
  ranks equivalents in three tiers (curated → exact-signature → partial
  heuristic) from the live node registry.
- Frontend (web/utfcn.js): on-add mode (Off / Suggest / Force auto-replace),
  bulk "Replace with core / available…" command + Extensions menu with a
  preview-then-confirm dialog, and a right-click single-node replace. The swap
  engine only rewires losslessly.
- mappings.json: 7 hand-verified curated rules mined from installed packs
  (essentials, KJNodes, WAS); user_mappings.json for user overrides.
- Docs + branding: README, icon and social banner (SVG + PNG), GPL-3.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,15 @@
+[project]
+name = "comfyui-utfcn"
+description = "Use The F***ing Core Nodes — suggests core (or otherwise-available) equivalents for custom nodes, and replaces them across a workflow after a preview."
+version = "1.0.0"
+license = { text = "GPL-3.0-or-later" }
+dependencies = []
+
+[project.urls]
+Repository = "https://github.com/ethanfel/ComfyUI-UTFCN"
+Documentation = "https://github.com/ethanfel/ComfyUI-UTFCN#readme"
+
+[tool.comfy]
+PublisherId = "ethanfel"
+DisplayName = "UTFCN — Use The Core Nodes"
+Icon = "https://raw.githubusercontent.com/ethanfel/ComfyUI-UTFCN/main/assets/icon.png"