feat(quality_dashboard): banner with overdue + critical (Task 4)

_fetch_banner_candidates collects (overdue) OR (critical-customer +
open) records per type. _critical_customer_ids reuses partner.x_fc_rush
and partner.x_fc_vip flags when defined (gracefully no-ops when
absent). _critical_badge returns RUSH/VIP/AEROSPACE/AS9100 label
when the banner reason is critical-customer (no badge when overdue).
_build_banner ranks: overdue first by oldest, then critical-customer
by oldest, takes top 6, reports total_matching.

build() now collects banner candidates from every section in one
pass + invokes _build_banner once.

Tests cover overdue hold pickup, 6-cap with overflow count, and
all_clear when DB is empty.

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

fusion_plating/fusion_plating_quality/tests/test_dashboard_snapshot.py

@@ -109,3 +109,64 @@ class TestDashboardSnapshotItems(TransactionCase):
         self.assertEqual(item['open_action']['res_model'],
                          'fusion.plating.quality.hold')
         self.assertEqual(item['open_action']['res_id'], hold.id)
+
+
+class TestDashboardSnapshotBanner(TransactionCase):
+    """Banner population + ranking."""
+
+    def _build(self):
+        from odoo.addons.fusion_plating_quality.controllers.fp_quality_dashboard \
+            import FpQualityDashboardSnapshot
+        return FpQualityDashboardSnapshot(self.env).build()
+
+    def test_banner_picks_up_overdue_hold(self):
+        from datetime import datetime, timedelta
+        if 'fusion.plating.quality.hold' not in self.env:
+            self.skipTest('fusion.plating.quality.hold not installed')
+        partner = self.env['res.partner'].create({'name': 'Cust'})
+        hold = self.env['fusion.plating.quality.hold'].create({
+            'partner_id': partner.id, 'state': 'on_hold', 'reason': 'old',
+        })
+        # Backdate create_date past the 3-day overdue threshold
+        old = datetime.now() - timedelta(days=5)
+        self.env.cr.execute(
+            "UPDATE fusion_plating_quality_hold SET create_date = %s WHERE id = %s",
+            (old, hold.id),
+        )
+        hold.invalidate_recordset(['create_date'])
+
+        snap = self._build()
+        self.assertFalse(snap['banner']['all_clear'])
+        self.assertEqual(snap['banner']['total_matching'], 1)
+        self.assertEqual(len(snap['banner']['items']), 1)
+        item = snap['banner']['items'][0]
+        self.assertEqual(item['type'], 'hold')
+        self.assertEqual(item['urgency'], 'overdue')
+
+    def test_banner_caps_at_6_with_overflow_count(self):
+        from datetime import datetime, timedelta
+        if 'fusion.plating.quality.hold' not in self.env:
+            self.skipTest('fusion.plating.quality.hold not installed')
+        partner = self.env['res.partner'].create({'name': 'Cust'})
+        Hold = self.env['fusion.plating.quality.hold']
+        # 8 overdue holds
+        old = datetime.now() - timedelta(days=5)
+        for i in range(8):
+            h = Hold.create({
+                'partner_id': partner.id, 'state': 'on_hold',
+                'reason': f'overdue {i}',
+            })
+            self.env.cr.execute(
+                "UPDATE fusion_plating_quality_hold SET create_date = %s WHERE id = %s",
+                (old, h.id),
+            )
+        snap = self._build()
+        self.assertEqual(len(snap['banner']['items']), 6)
+        self.assertEqual(snap['banner']['total_matching'], 8)
+        self.assertFalse(snap['banner']['all_clear'])
+
+    def test_banner_all_clear_when_zero(self):
+        snap = self._build()
+        # Empty DB — no overdue, no critical
+        self.assertTrue(snap['banner']['all_clear'])
+        self.assertEqual(snap['banner']['items'], [])