Update state machine documentation to use dash-separated naming

- Convert all state names from underscore to dash format in markdown documentation
- Ensures consistency across all documentation formats (dot, svg, markdown)
- All payment states now use dashes: confirmed-complete, underpaid-refunded, etc.
- Maintains consistency with the source dot file which is the canonical reference

This completes the documentation naming convention standardization.

Makefile

@@ -68,13 +68,18 @@ help:
 	@echo "  make sweep-all-doge         - Sweep ALL Dogecoin wallet funds to cold storage (dust collection)"
 	@echo "  make monero-transactions    - View recent wallet transactions"
 	@echo ""
+	@echo "DOCUMENTATION:"
+	@echo "  make docs/state-machine.dot.svg - Generate state machine diagram from .dot file"
+	@echo ""
 	@echo "CLEANUP:"
 	@echo "  make clean                  - Remove virtual environment"
 	@echo ""
 	@echo "For more info, see README.md and CRYPTO.rst"
 
-docs/state-machine.dot.svg:
+docs/state-machine.dot.svg: docs/state-machine.dot
+	@echo "Generating state machine diagram from docs/state-machine.dot..."
 	dot -Tsvg docs/state-machine.dot -o docs/state-machine.dot.svg
+	@echo "✓ Generated docs/state-machine.dot.svg"
 
 # -----------------------------------------------------------------------------
 # Environment Setup Targets