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/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating — Receiving & Inspection',
-    'version': '19.0.3.19.0',
+    'version': '19.0.3.20.0',
     'category': 'Manufacturing/Plating',
     'summary': 'Parts receiving, inspection, damage logging, and manufacturing gate.',
     'description': """