refactor: migrate _sql_constraints to models.Constraint (Odoo 19)

Odoo 19 removed the _sql_constraints list-of-tuples in favor of
models.Constraint class attributes. Migrate the three remaining sites
(spp_scoring, spp_metric, spp_analytics) and update the metric_category
test to introspect constraints via _table_objects.

Author: kneckinator

spp_analytics/models/service_cache.py

@@ -413,13 +413,10 @@ class AnalyticsCacheEntry(models.Model):
         help="When this result was computed",
     )
 
-    _sql_constraints = [
-        (
-            "cache_key_unique",
-            "UNIQUE(cache_key)",
-            "Cache key must be unique",
-        ),
-    ]
+    _cache_key_unique = models.Constraint(
+        "UNIQUE(cache_key)",
+        "Cache key must be unique",
+    )
 
     @api.model
     def cron_cleanup_expired(self):

spp_metric/models/metric_category.py

@@ -59,7 +59,7 @@ class MetricCategory(models.Model):
         help="Parent category for hierarchical organization",
     )
 
-    _sql_constraints = [("code_unique", "UNIQUE(code)", "Category code must be unique!")]
+    _code_unique = models.Constraint("UNIQUE(code)", "Category code must be unique!")
 
     @api.constrains("parent_id")
     def _check_parent_recursion(self):

spp_metric/tests/test_metric_category.py

@@ -30,7 +30,7 @@ def test_category_code_unique(self):
         This test verifies the constraint is defined in the model.
         """
         # Verify the SQL constraint is defined
-        constraints = {name for name, _, _ in self.env["spp.metric.category"]._sql_constraints}
+        constraints = {obj.name for obj in self.env["spp.metric.category"]._table_objects.values()}
         self.assertIn("code_unique", constraints, "SQL unique constraint should be defined for code field")
 
     def test_category_parent_child(self):

spp_scoring/models/scoring_invalid_value.py

@@ -57,13 +57,10 @@ class SppScoringInvalidValue(models.Model):
         ),
     )
 
-    _sql_constraints = [
-        (
-            "spp_scoring_invalid_value_name_uniq",
-            "unique(name)",
-            "An invalid-value entry with this string already exists.",
-        ),
-    ]
+    _name_uniq = models.Constraint(
+        "unique(name)",
+        "An invalid-value entry with this string already exists.",
+    )
 
     @api.constrains("name", "match_type")
     def _check_regex_compiles(self):