Add triple-tap lights-off and fix LED pin to D5

- Triple tap turns off LEDs; any subsequent tap or hold resumes the current show
- Change LED_DATA_PIN default from 6 to 5 across config, docs, and wiring diagram
- Fix Makefile upload to pass --input-dir so it uses the pre-built binary

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Makefile

@@ -44,7 +44,7 @@ upload: shows build
 		echo ""; \
 		exit 1; \
 	fi
-	arduino-cli upload --fqbn $(FQBN) --port $(PORT) $(SKETCH)
+	arduino-cli upload --fqbn $(FQBN) --port $(PORT) --input-dir $(BUILD_DIR) $(SKETCH)
 	@echo ""
 	@echo "  Uploaded to $(PORT). The show starts immediately."