Purge and check before resuming after a PAUSE

_RESUME_PRINT purges 40 mm with BLOBIFIER_CHECKED (instead of the 2 mm
unretract), so the nozzle is primed, wiped and checked before going back
to the print. A failed purge check raises an error that aborts the whole
resume, AFC_RESUME's restore included, so the printer stays paused; the
next RESUME checks again. RESUME PURGE=0 skips the purge.

The purge check records a failure in _PURGE_CHECK_CFG.last_failed, since
its PAUSE has no effect while the printer is already paused.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

macros/print/pause_resume.cfg

@@ -6,6 +6,10 @@
 #             -> RESUME_BASE, then AFC restores the saved position
 # RESUME is defined only here: heating/heat_soak.cfg used to define its own,
 # which replaced this one completely (no unretract, no fan restore).
+# After a PAUSE, _RESUME_PRINT purges into the Blobifier with the purge check
+# (BLOBIFIER_CHECKED, afc/purge_check.cfg) before going back to the print, so
+# the nozzle is primed and clean. If the check fails the resume stops with an
+# error and the printer stays paused. RESUME PURGE=0 resumes without the purge.
 
 # https://klipperscreen.readthedocs.io/en/latest/macros/#recommended
 [gcode_macro PAUSE]
@@ -33,10 +37,12 @@ gcode:
   HEAT_SOAK_RESUME ON_RESUME=_RESUME_PRINT {rawparams}
 
 [gcode_macro _RESUME_PRINT]
-description: Resume after PAUSE: unretract, restore the part fan, continue the print
+description: Resume after PAUSE: purge and check (or unretract), restore the part fan, continue the print
+variable_purge_length: 40      # mm purged before resuming after a PAUSE; 0 = only unretract
 gcode:
   {% set pause = printer["gcode_macro PAUSE"] %}
   {% set extrude = printer['gcode_macro _TOOLHEAD_PARK_PAUSE_CANCEL'].extrude %}
+  {% set purge = params.PURGE|default(purge_length)|float %}
   #### get VELOCITY parameter if specified ####
   {% if 'VELOCITY' in params|upper %}
     {% set get_params = ('VELOCITY=' + params.VELOCITY)  %}
@@ -47,9 +53,13 @@ gcode:
   # Only undo what PAUSE did; HEAT_SOAK pauses with PAUSE_BASE (no retract, no park)
   {% if pause.parked %}
     {% if printer.extruder.can_extrude|lower == 'true' %}
-      M83
-      G1 E{extrude} F2100
-      {% if printer.gcode_move.absolute_extrude |lower == 'true' %} M82 {% endif %}
+      {% if purge > 0 and 'gcode_macro BLOBIFIER' in printer %}
+        _RESUME_PURGE LENGTH={purge}     ; also replaces the unretract; stops here if the check fails
+      {% else %}
+        M83
+        G1 E{extrude} F2100
+        {% if printer.gcode_move.absolute_extrude |lower == 'true' %} M82 {% endif %}
+      {% endif %}
     {% else %}
       {action_respond_info("Extruder not hot enough")}
     {% endif %}
@@ -67,6 +77,27 @@ gcode:
   RESUME_BASE {get_params}
   _status_printing
 
+[gcode_macro _RESUME_PURGE]
+description: Purge LENGTH mm into the Blobifier (with the purge check if installed) before resuming
+gcode:
+  {% if 'gcode_macro BLOBIFIER_CHECKED' in printer %}
+    SET_GCODE_VARIABLE MACRO=_PURGE_CHECK_CFG VARIABLE=last_failed VALUE=False
+    BLOBIFIER_CHECKED PURGE_LENGTH={params.LENGTH}
+    _RESUME_PURGE_VERIFY
+  {% else %}
+    BLOBIFIER PURGE_LENGTH={params.LENGTH}
+  {% endif %}
+
+# Separate macro so the check result is read after the purge. Raising an
+# error aborts the whole RESUME (AFC_RESUME included): the printer stays
+# paused at the bucket and PAUSE.parked stays set, so the next RESUME purges
+# and checks again.
+[gcode_macro _RESUME_PURGE_VERIFY]
+gcode:
+  {% if printer["gcode_macro _PURGE_CHECK_CFG"].last_failed %}
+    {action_raise_error("Purge check failed: the print stays paused. Check the extruder and lane, then RESUME again (RESUME PURGE=0 resumes without purging).")}
+  {% endif %}
+
 [gcode_macro _TOOLHEAD_PARK_PAUSE_CANCEL]
 description: Helper: park toolhead used in PAUSE and CANCEL_PRINT
 variable_extrude: 2.0