[IMP] product_pricelist_total_margin: Add global_margin_type for min/max limits

- Add global_margin_type field in res.config.settings
  * Options: 'markup' (default) or 'margin' (commercial margin)
  * Determines how global min/max percentages are interpreted
- Refactor _apply_global_margin_limits():
  * Now receives price instead of margin percentage
  * Calculates min/max prices based on global_margin_type
  * Returns adjusted price instead of adjusted margin
  * Supports both markup and commercial margin formulas
- Update _compute_price() to apply limits after price calculation
- Update res_config_settings_views.xml to show global_margin_type selector
- Update help texts with examples for both calculation methods
- Add 2 new tests to validate global limits with commercial margin type:
  * test_global_minimum_with_commercial_margin_type
  * test_global_maximum_with_commercial_margin_type
- All 13 tests passing (11 existing + 2 new)

Example with global min 25%:
- Markup: Min price = Cost × 1.25
- Commercial Margin: Min price = Cost / 0.75 (ensures 25% margin on PVP)

product_pricelist_total_margin/tests/test_total_margin.py

@@ -411,3 +411,97 @@ class TestTotalMargin(TransactionCase):
             places=4,
             msg=f"Commercial margin should be 20%, got {commercial_margin * 100}%",
         )
+
+    def test_global_minimum_with_commercial_margin_type(self):
+        """Test global minimum margin with commercial margin calculation."""
+        # Set global minimum to 25% and type to commercial margin
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.min_percent", "25.0"
+        )
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.global_margin_type", "margin"
+        )
+
+        # Enable total margin (calculated: -5% + 25% = 20%, below min 25%)
+        self.item_chained.use_total_margin = True
+        self.item_chained.margin_type = "markup"  # Item uses markup
+
+        price = self.pricelist_chained._get_product_price(
+            product=self.product,
+            quantity=1.0,
+        )
+
+        # Expected: Global limit is interpreted as commercial margin
+        # Min 25% commercial margin: PVP = Cost / (1 - 0.25) = 4.68 / 0.75 = 6.24
+        # Item calculates 20% markup: 4.68 * 1.20 = 5.616, but global min forces 6.24
+        expected_price = 4.68 / 0.75
+        self.assertAlmostEqual(
+            price,
+            expected_price,
+            places=2,
+            msg=f"Global minimum (commercial margin 25%) should give {expected_price}, got {price}",
+        )
+
+        # Verify the actual commercial margin is 25%
+        commercial_margin = (price - 4.68) / price
+        self.assertAlmostEqual(
+            commercial_margin,
+            0.25,
+            places=4,
+            msg=f"Commercial margin should be 25%, got {commercial_margin * 100}%",
+        )
+
+        # Clean up
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.min_percent", "0.0"
+        )
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.global_margin_type", "markup"
+        )
+
+    def test_global_maximum_with_commercial_margin_type(self):
+        """Test global maximum margin with commercial margin calculation."""
+        # Set global maximum to 15% and type to commercial margin
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.max_percent", "15.0"
+        )
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.global_margin_type", "margin"
+        )
+
+        # Enable total margin (calculated: -5% + 25% = 20%, above max 15%)
+        self.item_chained.use_total_margin = True
+        self.item_chained.margin_type = "margin"  # Item uses commercial margin
+
+        price = self.pricelist_chained._get_product_price(
+            product=self.product,
+            quantity=1.0,
+        )
+
+        # Expected: Global limit is interpreted as commercial margin
+        # Max 15% commercial margin: PVP = Cost / (1 - 0.15) = 4.68 / 0.85 = 5.506
+        # Item calculates 20% margin: 4.68 / 0.80 = 5.85, but global max limits to 5.506
+        expected_price = 4.68 / 0.85
+        self.assertAlmostEqual(
+            price,
+            expected_price,
+            places=2,
+            msg=f"Global maximum (commercial margin 15%) should give {expected_price}, got {price}",
+        )
+
+        # Verify the actual commercial margin is 15%
+        commercial_margin = (price - 4.68) / price
+        self.assertAlmostEqual(
+            commercial_margin,
+            0.15,
+            places=4,
+            msg=f"Commercial margin should be 15%, got {commercial_margin * 100}%",
+        )
+
+        # Clean up
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.max_percent", "0.0"
+        )
+        self.env["ir.config_parameter"].sudo().set_param(
+            "product_pricelist_total_margin.global_margin_type", "markup"
+        )