Split permissions_resources_sql() into 5 for readability

Also remove an obsolete test that caused trouble with the new split plugin hook.

Closes #2570

tests/test_actions_sql.py

@@ -315,62 +315,3 @@ async def test_sql_does_filtering_not_python(test_ds):
 
     finally:
         pm.unregister(plugin, name="test_plugin")
-
-
-@pytest.mark.asyncio
-async def test_no_permission_rules_returns_correct_schema():
-    """
-    Test that when no permission rules exist, the empty result has correct schema.
-
-    This is a regression test for a bug where the empty result returned only
-    2 columns (parent, child) instead of the documented 3 columns
-    (parent, child, reason), causing schema mismatches.
-
-    See: https://github.com/simonw/datasette/pull/2515#discussion_r2457803901
-    """
-    from datasette.utils.actions_sql import build_allowed_resources_sql
-
-    # Create a fresh datasette instance
-    ds = Datasette()
-    await ds.invoke_startup()
-
-    # Add a test database
-    db = ds.add_memory_database("testdb")
-    await db.execute_write(
-        "CREATE TABLE IF NOT EXISTS test_table (id INTEGER PRIMARY KEY)"
-    )
-    await ds._refresh_schemas()
-
-    # Temporarily unregister all permission_resources_sql providers to simulate no rules
-    hook_caller = pm.hook.permission_resources_sql
-    hookimpls = hook_caller.get_hookimpls()
-    removed_plugins = [
-        (impl.plugin_name, impl.plugin) for impl in hookimpls if impl.plugin is not None
-    ]
-
-    for plugin_name, _ in removed_plugins:
-        pm.unregister(name=plugin_name)
-
-    try:
-        # Call build_allowed_resources_sql directly which will hit the no-rules code path
-        sql, params = await build_allowed_resources_sql(
-            ds, actor={"id": "nobody"}, action="view-table"
-        )
-
-        # Execute the query to verify it has correct column structure
-        result = await ds.get_internal_database().execute(sql, params)
-
-        # Should have 3 columns: parent, child, reason
-        # This assertion would fail if the empty result only had 2 columns
-        assert (
-            len(result.columns) == 3
-        ), f"Expected 3 columns, got {len(result.columns)}: {result.columns}"
-        assert result.columns == ["parent", "child", "reason"]
-
-        # Should have no rows (no rules = no access)
-        assert len(result.rows) == 0
-
-    finally:
-        # Restore original plugins in the order they were removed
-        for plugin_name, plugin in removed_plugins:
-            pm.register(plugin, name=plugin_name)