feat(plating): Phase 1 — plant-view kanban data model foundation

PV-T1: fp.work.centre.area_kind Selection (9 floor columns)
PV-T2: fp.job.step.area_kind compute + _STEP_KIND_TO_AREA fallback
       (covers all 30+ step kinds in the project library, plus the
       spec D4 rule that de_mask folds into de_racking)
PV-T3: fp.job.step.last_activity_at + write hook + message_post
       override + fp.job.step.move.create() hook + _fp_is_idle helper
PV-T4: res.users.paired_work_centre_ids M2M (single-station for MVP,
       forward-compatible for Phase 2 multi-station picker)
PV-T5: res.config.settings.x_fc_shopfloor_layout feature flag backed
       by ir.config_parameter for the landing-action resolver

Migrations:
  fusion_plating 19.0.21.0.0      — backfill area_kind from kind
  fusion_plating_jobs 19.0.10.24.0 — backfill last_activity_at

Deployed + verified on entech:
  - 9/9 fp.work.centre rows have area_kind set
  - 400/400 fp.job.step rows have area_kind + last_activity_at
  - paired_work_centre_ids M2M relation table created
  - All 271 modules loaded cleanly, registry rebuilt in 27s

Part of the 2026-05-23 Shop Floor plant-view kanban redesign.
Plan: docs/superpowers/plans/2026-05-23-shopfloor-plant-view-plan.md
Spec: docs/superpowers/specs/2026-05-23-shopfloor-plant-view-design.md

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

fusion_plating/fusion_plating/models/fp_job_step_move.py

@@ -77,6 +77,27 @@ class FpJobStepMove(models.Model):
         string='Transition Input Values',
     )
 
+    @api.model_create_multi
+    def create(self, vals_list):
+        """Stamp last_activity_at on from_step + to_step so the plant-view
+        idle gate (S16) sees moves as activity. Without this, a step that
+        only ever gets moves (no chatter, no state edits) eventually
+        trips the 8-hour idle warning falsely.
+        """
+        moves = super().create(vals_list)
+        Step = self.env['fp.job.step']
+        step_ids = set()
+        for m in moves:
+            if m.from_step_id:
+                step_ids.add(m.from_step_id.id)
+            if m.to_step_id:
+                step_ids.add(m.to_step_id.id)
+        if step_ids:
+            Step.browse(list(step_ids)).sudo().with_context(
+                tracking_disable=True,
+            ).write({'last_activity_at': fields.Datetime.now()})
+        return moves
+
     # ------------------------------------------------------------------
     # S23 — required transition-input gate
     # ------------------------------------------------------------------

fusion_plating/fusion_plating/models/fp_work_centre.py

@@ -48,6 +48,26 @@ class FpWorkCentre(models.Model):
         required=True,
         default='other',
     )
+    area_kind = fields.Selection(
+        [
+            ('receiving',  'Receiving'),
+            ('masking',    'Masking'),
+            ('blasting',   'Blasting'),
+            ('racking',    'Racking'),
+            ('plating',    'Plating'),
+            ('baking',     'Baking'),
+            ('de_racking', 'De-Racking'),
+            ('inspection', 'Final inspection'),
+            ('shipping',   'Shipping'),
+        ],
+        string='Floor Column',
+        help='Which Shop Floor column this work centre belongs to. '
+             'Drives the plant-view kanban grouping — any job whose '
+             'active step uses this work centre routes into this column. '
+             'See docs/superpowers/specs/2026-05-23-shopfloor-plant-view-'
+             'design.md §4.2 for the mapping rules.',
+        index=True,
+    )
     cost_per_hour = fields.Monetary(
         currency_field='currency_id',
         help='Used for fp.job.step cost rollups.',