fix(ui): string-valued input_sr combo so the arrows cycle correctly

Integer-valued combos break ComfyUI's arrow navigation: indexOf(value) fails
on the int/serialized-value mismatch, returns -1, and the widget snaps to
index 0 (8000) every click. Use string options ("8000".."24000"); the code
already does int(input_sr) everywhere, so behavior is unchanged. Updated the
example workflows' widgets_values to strings to match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

example_workflows/universr_video.json

@@ -50,7 +50,7 @@
         {"name": "spectrogram", "type": "IMAGE", "links": [], "slot_index": 1}
       ],
       "properties": {"Node name for S&R": "UniverSRSampler"},
-      "widgets_values": [16000, "midpoint", 4, 2.0, 0, "randomize", 10.0, 0.5, 1.0, false, true]
+      "widgets_values": ["16000", "midpoint", 4, 2.0, 0, "randomize", 10.0, 0.5, 1.0, false, true]
     },
     {
       "id": 4,