Fix print.calibration docs and add v1's missing report schema

Confirmed live: both BambuMQTT versions reply to a calibration request
with a dedicated print.calibration report, not just push_status - the
v1 request schema's own description said the opposite ("printer responds
with push_status instead of calibration"), and v2's report schema framed
this as a v1-vs-v2 contrast that no longer holds. Both descriptions
corrected; the printer does still send ordinary push_status updates
alongside the dedicated report as calibration progresses, same as any
other print job, not instead of it.

Added v1/report/print/calibration.schema.json (only existed for v2
before) and wired it into v1/report.schema.json's print category
dispatcher, which never listed it since the file didn't exist.

schemas/bambulab/v1/report.schema.json

@@ -26,6 +26,7 @@
     "print": {
       "oneOf": [
         { "$ref": "report/print/ams_change_filament.schema.json" },
+        { "$ref": "report/print/calibration.schema.json" },
         { "$ref": "report/print/ams_control.schema.json" },
         { "$ref": "report/print/ams_filament_setting.schema.json" },
         { "$ref": "report/print/ams_get_rfid.schema.json" },