chore: add graph explorer make target

Makefile

@@ -0,0 +1,21 @@
+PYTHON ?= python3
+REGISTRY_DB ?= .railiance-fabric/registry.sqlite3
+HOST ?= 127.0.0.1
+PORT ?= 8765
+
+.DEFAULT_GOAL := help
+
+.PHONY: help graph-explorer registry
+
+help:
+	@printf "Available targets:\n"
+	@printf "  make graph-explorer  Start the registry-backed graph explorer on HOST:PORT.\n"
+	@printf "                       Defaults: HOST=$(HOST), PORT=$(PORT), REGISTRY_DB=$(REGISTRY_DB)\n"
+	@printf "  make registry        Alias for graph-explorer.\n"
+
+graph-explorer:
+	@mkdir -p $(dir $(REGISTRY_DB))
+	@echo "Starting Railiance Fabric graph explorer at http://$(HOST):$(PORT)/ui/graph-explorer"
+	$(PYTHON) -m railiance_fabric.server --db "$(REGISTRY_DB)" --host "$(HOST)" --port "$(PORT)"
+
+registry: graph-explorer