fix(plating): chatter HTML rendering + workflow stage banner UX

Two fixes from a single SO walkthrough screenshot:

**1. "Current stage" banner**
- Was placed `inside sheet` so it rendered at the BOTTOM of the form
  where users miss it. Moved to `before form/header` (same xpath
  pattern as the Account Hold banner) — now it's the first thing
  visible above the SO header.
- Was still showing "Shipped — awaiting invoice" after the invoice
  was posted because `_compute_workflow_stage` only advanced to
  `complete` when shipped + ALL paid; an unpaid posted invoice left
  the SO stuck on `shipped`. Added an `invoicing` branch: shipped +
  has_posted_invoice → invoicing. Banner invisible-list now also
  includes `invoicing` and `paid`, so the banner only shows for
  in-progress steps.

**2. Chatter messages rendering raw HTML tags as text**
Odoo 19 escapes any string passed to `message_post(body=...)`
unless wrapped in `markupsafe.Markup`. We had ~10 places posting
HTML (`<a href>`, `<b>`, `<br/>`, `<code>`, `<pre>`) that all
showed up as `&lt;a href=...&gt;` literal text in the chatter.

Wrapped each one with `Markup(_(...))` so the tags render. Files
touched:

- fusion_plating_bridge_mrp/models/sale_order.py
  (auto-MO failure code block, "Draft MO created" link,
   "Job assigned to <b>" message)
- fusion_plating_bridge_mrp/models/mrp_production.py
  ("Recipe steps" pre/br block on each WO)
- fusion_plating_bridge_mrp/models/fp_proficiency.py
  (operator promotion announcement)
- fusion_plating_configurator/models/fp_quote_configurator.py
  (SO link, 3D model attached, drawing attached, save to catalog)
- fusion_plating_configurator/models/fp_part_catalog.py
  (3D/drawing change tracking + propagation to linked quotes)
- fusion_plating_portal/models/fp_quote_request.py
  (RFQ → SO link)
- fusion_plating_quality/models/fp_quality_hold.py
  (hold status change)
- fusion_plating_shopfloor/controllers/manager_controller.py
  (worker / tank / manager-takeover assignments)

Verified on entech: SO S00038 stage now reads `invoicing` (banner
hidden), and a freshly posted message shows `<a href>` and `<b>`
as actual link + bold instead of escaped text.

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

fusion_plating/fusion_plating_bridge_mrp/views/sale_order_views.xml

@@ -92,12 +92,15 @@
                         help="Close the open delivery record(s) and fire auto-invoice per strategy."/>
             </xpath>
 
-            <!-- Show the workflow stage on the sheet so users always
-                 know what step they're on (readonly banner). -->
-            <xpath expr="//sheet" position="inside">
+            <!-- Workflow stage banner — sits ABOVE the form header so it's
+                 the first thing users see, matches the Account Hold banner.
+                 Hidden for terminal states (invoicing/paid/complete/cancelled)
+                 and the initial draft so it only shows when there's an
+                 active in-progress step. -->
+            <xpath expr="//form/header" position="before">
                 <div class="alert alert-info mb-2"
                      style="border-radius: 6px;"
-                     invisible="x_fc_workflow_stage in ('draft', 'complete', 'cancelled')">
+                     invisible="x_fc_workflow_stage in ('draft', 'invoicing', 'paid', 'complete', 'cancelled')">
                     <i class="fa fa-compass me-2"/>
                     <strong>Current stage:</strong>
                     <field name="x_fc_workflow_stage" readonly="1" nolabel="1" class="ms-1"/>