fix(receiving): drop dead staged state — Option B (draft→counted→closed)

Reported 2026-05-20: the receiving state machine had four states
(draft → counted → staged → closed) where the middle pair was pure
ceremony. Real-usage data on entech:

  state distribution: 14 draft, 4 closed (zero `staged` records)
  median dwell counted → staged: 11 seconds
  median dwell staged  → closed: 4 minutes

`staged` captured no fields, fired no gates, mapped to the same SO
`x_fc_receiving_status='partial'` as `counted`. Pure click-through.

Cleanup:
- State Selection retains `staged` as `Staged (legacy)` so historical
  records remain readable; new transitions never write it.
- statusbar_visible drops it from the chevron header.
- action_mark_staged becomes a thin shim that advances counted →
  closed directly (any old button binding still works).
- action_close now accepts `counted` as a valid source state (was
  previously only `staged` / legacy `accepted` / `resolved`).
- View: "Stage for Racking" button removed. "Close" button renamed
  to "Close — Racking Confirmed" so the racking-crew confirmation
  meaning stays obvious.
- _update_so_receiving_status mapping unchanged for legacy `staged`
  (still maps to partial) — only the comment block updated to
  describe the new canonical flow.

Migration 19.0.3.20.0 advances any `staged` records to `closed`
and syncs the linked SO's x_fc_receiving_status to `received` so
downstream gates (job step start, mark_done qty check, cert
creation) don't see a stale "partial" status.

Module: fusion_plating_receiving 19.0.3.19.0 → 19.0.3.20.0.

Tests: TestQtyReceivedPropagation updated — 5 tests dropped the
action_mark_staged() call, walk draft → counted → closed directly.
All 11 tests green (carrier 6 + propagation 5).

Verified on entech: existing 14 draft + 4 closed records untouched.
Direct draft → counted → closed transition works end-to-end on
RCV-30041 (was the test target).

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

fusion_plating/fusion_plating_receiving/migrations/19.0.3.20.0/post-migrate.py

@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc.
+# License OPL-1 (Odoo Proprietary License v1.0)
+#
+# 2026-05-20 — `staged` state retirement.
+#
+# Drop `staged` from the active receiving state machine. The state had
+# zero downstream effect (same SO mapping as counted), no captured
+# data, and median dwell of 11 sec — pure ceremony between Counted
+# and Closed. Any existing records currently sitting in `staged` get
+# promoted to `closed` (they're already past the box-count step;
+# closed is the next logical resting place).
+#
+# `staged` stays in the Selection as a (legacy) value so historical
+# records that ever held it can still be read — we just don't write
+# to it anymore. The view's statusbar_visible drops it.
+
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+def migrate(cr, version):
+    cr.execute("""
+        UPDATE fp_receiving
+           SET state = 'closed'
+         WHERE state = 'staged'
+    """)
+    n = cr.rowcount
+    if n:
+        _logger.info(
+            '`staged` retirement: advanced %d receiving record(s) to '
+            'closed (state was dead ceremony, median dwell 11 sec).',
+            n,
+        )
+        # Mirror the new state onto the linked sale orders so downstream
+        # gates (job step start, mark_done qty check, cert creation)
+        # see the right `received` status without waiting for the next
+        # state-transition action.
+        cr.execute("""
+            UPDATE sale_order so
+               SET x_fc_receiving_status = 'received'
+              FROM fp_receiving r
+             WHERE r.sale_order_id = so.id
+               AND r.state = 'closed'
+               AND so.x_fc_receiving_status != 'received'
+        """)
+        if cr.rowcount:
+            _logger.info(
+                '`staged` retirement: synced %d sale_order.x_fc_receiving'
+                '_status to "received".', cr.rowcount,
+            )