fix(plating): UAT-caught UX annoyances + lurking bugs

Five fixes from the end-to-end UAT debrief:

1. Menu discoverability (HIGH)
   Added a prominent "+ New Direct Order" button in the Sale Orders
   list header toolbar (class=btn-primary, display=always). The
   existing menuitem at Plating > Sales > New Direct Order was
   buried in a submenu that didn't always expand; the toolbar
   button is a guaranteed entry point from the most common screen.

2. Escape/X destroys wizard state (HIGH)
   Added a prominent info banner at the top of the wizard form:
   "Changes are not saved until you click Create & Confirm Order.
   Closing this window (Esc or X) discards your entries." The
   Cancel button now has confirm="Discard this order? All header
   data and line items will be lost." so the intentional-cancel
   path also prompts.

3. Shell/cron crash in _fp_auto_create_mo (MEDIUM)
   bridge_mrp/models/sale_order.py:232-264 used _() inside list
   comprehensions to format the internal chatter summary of newly
   created / adopted MOs. _() resolves language from env.context,
   which is empty in odoo-shell and cron contexts — triggering a
   translate.get_text_alias crash AFTER the MOs had been created.
   These strings are internal audit log text, not user-facing UI;
   dropped the _() wrappers so the message builds safely from any
   context. Same for the per-group error-message on savepoint
   rollback.

4. Misleading "100%" margin (MEDIUM)
   x_fc_margin_percent displayed 100% on every SO because the cost
   rollup from fp.coating.config.unit_cost isn't populated yet.
   Added x_fc_margin_available Boolean (True only when at least
   one line's coating has a non-zero unit_cost). The SO Plating
   tab now hides the margin numbers when margin_available=False
   and shows an inline muted note: "Margin n/a — coating cost
   rollup not yet populated on any line's treatment."

5. Account Hold banner too loud (LOW)
   fusion_plating_invoicing was injecting a full-height danger
   alert above every SO header. Slimmed it to a one-line compact
   alert with icon: "Account Hold — SO confirmation, invoicing
   and shipping are blocked for non-managers." Half the vertical
   footprint, less visual competition with the Plating chip bar.

Verified via UAT on S00071.

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

fusion_plating/fusion_plating_configurator/models/sale_order.py

@@ -113,6 +113,12 @@ class SaleOrder(models.Model):
         string='Margin %',
         compute='_compute_margin',
     )
+    x_fc_margin_available = fields.Boolean(
+        string='Margin Available',
+        compute='_compute_margin',
+        help='False when no order line has a costed coating — the '
+             'margin fields should render "n/a" in the UI.',
+    )
 
     x_fc_workorder_count = fields.Integer(
         string='Active WOs',
@@ -486,24 +492,34 @@ class SaleOrder(models.Model):
 
     @api.depends('order_line.price_subtotal', 'amount_untaxed')
     def _compute_margin(self):
-        """Simple margin: untaxed total minus rolled-up cost from coating configs.
+        """Margin = untaxed total − rolled-up cost from coating configs.
 
         x_fc_margin_percent is stored as a fraction (0.0 - 1.0) so the
-        widget='percentage' formats it correctly (a 100% margin reads
-        as 100%, not 10000%).
+        widget='percentage' formats 100% as 100%, not 10000%.
+
+        x_fc_margin_available is False when NO line has a costed coating
+        (i.e. fp.coating.config.unit_cost isn't populated anywhere). The
+        UI should render margin fields as "n/a" in that case rather than
+        showing a misleading 100%.
         """
         for rec in self:
+            has_cost_data = False
             cost = 0.0
             for line in rec.order_line:
-                if line.x_fc_coating_config_id:
-                    cost_per_unit = getattr(
-                        line.x_fc_coating_config_id, 'unit_cost', 0.0,
-                    ) or 0.0
-                    cost += cost_per_unit * (line.product_uom_qty or 0)
+                cc = line.x_fc_coating_config_id
+                if not cc:
+                    continue
+                if 'unit_cost' not in cc._fields:
+                    continue
+                if cc.unit_cost:
+                    has_cost_data = True
+                cost_per_unit = cc.unit_cost or 0.0
+                cost += cost_per_unit * (line.product_uom_qty or 0)
+            rec.x_fc_margin_available = has_cost_data
             rec.x_fc_margin_amount = (rec.amount_untaxed or 0) - cost
             rec.x_fc_margin_percent = (
                 (rec.x_fc_margin_amount / rec.amount_untaxed)
-                if rec.amount_untaxed else 0.0
+                if (rec.amount_untaxed and has_cost_data) else 0.0
             )
 
     @api.onchange('upload_rfq_file')