fix(bridge_mrp): WO recipe generator + demo work-order backfill

bridge_mrp._generate_workorders_from_recipe was writing 'description'
on mrp.workorder, which doesn't exist in Odoo 19 — instead the step
instructions now post to each WO's chatter after bulk create, which
is where the operator sees them anyway.

Demo seeder now creates the full WO chain:
- 9 MRP work centres paired with 9 FP work centres (FP-QUEUE, -RACK,
  -MASK, -EN, -BAKE, -INSP, -DERACK, -DEMASK, -POSTBAKE) with
  costs_hour set so actuals-vs-quoted margin can compute.
- Wires the existing ENP-ALUM-BASIC recipe's 9 operation nodes to
  those FP work centres by matching names.
- Links every coating config to the recipe so the auto-assign hook
  (mrp.production.action_confirm → _auto_assign_recipe_from_so) has
  something to pull.
- Backfills work orders on all existing demo MOs: calls the generator
  once recipe is set. For historical (done) MOs, marks all their WOs
  done with backdated durations (25-90 min). For the Cyclone active
  MO, sets a realistic progression: first WO done, second in progress
  (priority: Hot), rest in 'ready'.

Verified: 90 WOs live, 10 per work centre. One MO shows the full
progression state mix. WO Traveller PDF renders (132KB) — both
portrait + landscape variants still work.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_bridge_mrp/models/mrp_production.py

@@ -288,6 +288,7 @@ class MrpProduction(models.Model):
 
             # Walk tree and collect operation WO values
             wo_vals_list = []
+            wo_steps = {}  # {sequence: instruction text} — posted to WO chatter after create
             seq_counter = [10]  # mutable for closure, increments by 10
 
             def _is_node_included(node):
@@ -341,14 +342,19 @@ class MrpProduction(models.Model):
                             steps.append(line)
                             step_num += 1
 
+                    # Odoo 19 mrp.workorder has no 'description' field;
+                    # store step instructions on the operation via the
+                    # existing `operation_id.note` path, or just log them
+                    # to the WO chatter.
                     wo_vals_list.append({
                         'production_id': production.id,
                         'name': node.name,
                         'workcenter_id': mrp_wc,
                         'duration_expected': node.estimated_duration or 0,
                         'sequence': seq_counter[0],
-                        'description': '\n'.join(steps) if steps else '',
                     })
+                    if steps:
+                        wo_steps[seq_counter[0]] = '\n'.join(steps)
                     seq_counter[0] += 10
 
                 elif node.node_type in ('recipe', 'sub_process'):
@@ -362,7 +368,15 @@ class MrpProduction(models.Model):
 
             # Bulk create work orders
             if wo_vals_list:
-                WorkOrder.create(wo_vals_list)
+                created_wos = WorkOrder.create(wo_vals_list)
+                # Post step instructions to each WO's chatter where present
+                for wo in created_wos:
+                    steps_txt = wo_steps.get(wo.sequence)
+                    if steps_txt:
+                        wo.message_post(
+                            body=_('<b>Recipe steps:</b><br/><pre>%s</pre>') % steps_txt,
+                            subtype_xmlid='mail.mt_note',
+                        )
                 production.message_post(
                     body=_('%d work orders generated from recipe "%s".') % (
                         len(wo_vals_list), production.x_fc_recipe_id.name),