MAINT-11 round 2: disable the cycle buttons that cannot work

Stop cycle is disabled on a battery that is not cycling. Start cycle is
disabled while any battery cycles and on a switched-off battery. Page only;
the add-on still refuses each of these. DECISIONS notes the one-battery case.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bdqr7PiaHcBnzPituu2yTC

goodwe_controller/DECISIONS/MAINT-11-cycle-per-battery.md

@@ -32,3 +32,6 @@ queues by waiting time, so nothing is lost.
   (SAFETY-73); its drain waits. The per-battery start does the same.
 - A start on the battery that is already cycling is refused as "busy", where
   the bare button restarts its drain. The bare button is unchanged.
+- At one battery, a request that names the battery uses the new path, so a
+  second start is refused instead of restarting the drain. Nothing sends a name
+  at one battery, and the bare request is unchanged.