Name it Gyre - Sand Art Table

README, build guide, software README, web page header and title, jog page,
desktop alerts and the start-up message now say Gyre. The repo, the Python
package and its commands keep their names (sandTable, python3 -m sandtable),
so links and setups keep working. New web page screenshot.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

BUILD.md

@@ -1,6 +1,6 @@
-# Build guide
+# Gyre - build guide
 
-This guide takes you from a pile of parts to a table drawing in sand. It follows the order that works: case first, then the electronics, the arm on the bench, the arm into the table, a test run without sand, and finally the floor, sand and glass.
+This guide takes you from a pile of parts to Gyre, a sand art table, drawing in sand. It follows the order that works: case first, then the electronics, the arm on the bench, the arm into the table, a test run without sand, and finally the floor, sand and glass.
 
 ![the arm, bolted to its hub, with the counterweight](docs/arm-bolted-counterweight.png)