feat: split returning support into DML-specific flags for PostgreSQL dialect

Author: vistart

.github/workflows/test.yml

@@ -77,9 +77,9 @@ jobs:
           pip install -r requirements.txt
           pip install -r requirements-dev.txt
 
-      - name: Install activerecord and testsuite from PyPI
+      - name: Install activerecord and testsuite
         run: |
-          pip install rhosocial-activerecord==1.0.0.dev26
+          pip install git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev27
           pip install rhosocial-activerecord-testsuite==1.0.0.dev13
 
       - name: Create postgres scenario config

src/rhosocial/activerecord/backend/impl/postgres/dialect.py

@@ -472,9 +472,17 @@ def supports_materialized_cte(self) -> bool:
         """MATERIALIZED hint is supported since PostgreSQL 12."""
         return self.version >= (12, 0, 0)
 
-    def supports_returning_clause(self) -> bool:
-        """RETURNING clause is supported since PostgreSQL 8.2."""
-        return True  # Supported in all modern versions
+    def supports_returning_insert(self) -> bool:
+        """RETURNING clause is supported for INSERT since PostgreSQL 8.2."""
+        return self.version >= (8, 2, 0)
+
+    def supports_returning_update(self) -> bool:
+        """RETURNING clause is supported for UPDATE since PostgreSQL 8.2."""
+        return self.version >= (8, 2, 0)
+
+    def supports_returning_delete(self) -> bool:
+        """RETURNING clause is supported for DELETE since PostgreSQL 8.2."""
+        return self.version >= (8, 2, 0)
 
     def supports_window_functions(self) -> bool:
         """Window functions are supported since PostgreSQL 8.4."""