Add Pause to the browser client's Sud controls

Mirrors client/brewpi_gui.py's actionPause: btn-sud-pause sends
{"Sud": {"Pause": true}} and is only enabled while actually running
(not idle, not already paused), matching update_sud_actions()'s
enabled/disabled logic - Start already doubles as Resume while paused,
so no separate Resume control is needed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0189FkmyJkY77HqsNomr1DwV

README.md

@@ -540,11 +540,10 @@ unresolved - every step still needs `default.step` merged in), and the
 `StepPlate`/`_update_step_plates()`/`update_status_step_label()` logic
 behind the Progress tab and status line. New/Load/Save (a plain
 `<input type="file">`/`FileReader` and a `Blob`/`<a download>` standing in
-for the desktop app's native file dialogs), Start/Stop, and Confirm (a
-plain `<dialog>` pops with the step's message on `WAIT_USER` and sends
+for the desktop app's native file dialogs), Start/Pause/Stop, and Confirm
+(a plain `<dialog>` pops with the step's message on `WAIT_USER` and sends
 Confirm when dismissed) are all wired up too - see `web/TODO.md` for
-what's still missing (Pause, and more). Deliberately deferred rather than
-stubbed: the
+what's still missing. Deliberately deferred rather than stubbed: the
 Automatic tab's forecast-vs-actual plot and the live Plot tab's strip
 charts - both need a charting approach, revisit once Manual + Progress are
 validated.