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>

software/sandtable/cli.py

@@ -52,7 +52,7 @@ def alert(title, msg):
         return
     try:
         import subprocess
-        subprocess.run(['notify-send', '-u', 'critical', '-a', 'Sand table', title, msg],
+        subprocess.run(['notify-send', '-u', 'critical', '-a', 'Gyre', title, msg],
                        timeout=5, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
     except Exception:
         pass
@@ -71,15 +71,15 @@ def guarded(fn):
     try:
         return fn()
     except SwitchTripped as e:
-        alert('Sand table stopped: home switch pressed',
+        alert('Gyre stopped: home switch pressed',
               f'{e}.\nThe motors were stopped at once. Check the arm, belts and carriage, then run '
               f'`play` again; it homes first.')
         sys.exit(1)
     except GrblError as e:
-        alert('Sand table stopped', str(e))
+        alert('Gyre stopped', str(e))
         sys.exit(1)
     except OSError as e:        # pyserial's SerialException is an OSError: the USB link dropped
-        alert('Sand table: USB connection lost',
+        alert('Gyre: USB connection lost',
               f'{e}\nThe Uno restarts when it is plugged back in, so the table stops where it is. '
               f'Run `play` again; it homes first.')
         sys.exit(1)