feat(plating): wire deferred UoM defaults — bake oven, bake window, coating, tank

Follow-up to the company-level UoM defaults commit. Wires four more
unit-bearing fields to inherit from res.company defaults at create-time.

**1. fp.bake.oven**
  • New `target_temp_uom` (°F / °C) — defaults from
    company.x_fc_default_temp_uom.
  • View: target_temp_min / max now render with a unit picker on the
    same row instead of unitless floats. Rule of thumb: "350–380 °F".

**2. fp.bake.window**
  • New `bake_temp_uom` — defaults from company.x_fc_default_temp_uom.
  • View: replaced hardcoded `°F` span with a live unit picker so the
    label matches whatever unit was actually recorded.

**3. fp.coating.config**
  • New `bake_temperature_uom` — defaults from company.
  • Removed hardcoded "Bake Temperature (°F)" label; the field is
    now unit-agnostic and the unit travels with the value.

**4. fp.tank.volume_uom**
  • Default now derives from company.x_fc_default_volume_uom via a
    small mapping (gal → gal_us, L → l, imp_gal → gal_imp). The
    selection itself stays the same — tanks already supported all
    common volume units; we just pre-pick the right one per company.

**Verified end-to-end** (scripts/fp_uom_smoke2.py):
  • Switching company default to °C + Litres
  • New oven gets C ✓
  • New bake window gets C ✓
  • New coating config gets C ✓
  • New tank gets `l` ✓ (mapped from company `L`)
  • Restored defaults afterwards

Existing records keep their stored uom — no surprise mutation.

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

fusion_plating/fusion_plating_shopfloor/models/fp_bake_oven.py

@@ -50,6 +50,13 @@ class FpBakeOven(models.Model):
         string='Target Temp Max',
         help='Upper bound of target oven temperature.',
     )
+    target_temp_uom = fields.Selection(
+        [('F', '°F'), ('C', '°C')],
+        string='Temp Unit',
+        default=lambda self: self.env.company.x_fc_default_temp_uom or 'F',
+        help='Unit for the target temp range. Defaults to the company '
+             'preference (Settings → Fusion Plating → Units of Measure).',
+    )
     chart_recorder_ref = fields.Char(
         string='Chart Recorder Ref',
         help='Serial / asset reference of the chart recorder providing trace evidence.',

fusion_plating/fusion_plating_shopfloor/models/fp_bake_window.py

@@ -110,6 +110,13 @@ class FpBakeWindow(models.Model):
     )
     bake_temp = fields.Float(
         string='Bake Temp',
+        help='Setpoint temperature recorded for the relief bake. '
+             'Unit follows bake_temp_uom (defaults from company).',
+    )
+    bake_temp_uom = fields.Selection(
+        [('F', '°F'), ('C', '°C')],
+        string='Temp Unit',
+        default=lambda self: self.env.company.x_fc_default_temp_uom or 'F',
     )
     bake_duration_hours = fields.Float(
         string='Bake Duration (hours)',