feat: generated and identity columns for mssql, sqlite, drizzle, typeorm, bun and gorm readers

- mssql: write computed columns (AS (expr) PERSISTED) and identity; read computed definition and identity
- sqlite: write GENERATED ALWAYS AS (expr) STORED; read generated columns via table_xinfo and parse the expression
- drizzle: generatedAlwaysAs / generated(Always|ByDefault)AsIdentity, read and write
- typeorm: asExpression/generatedType and identity decorators, read and write; decorator scan is now quote-aware
- bun, gorm readers: read generated and identity markers
- readmes updated

pkg/readers/mssql/reader_test.go

@@ -85,3 +85,18 @@ func TestConvertMSSQLToCanonical(t *testing.T) {
 		})
 	}
 }
+
+func TestTrimOuterParens(t *testing.T) {
+	tests := map[string]string{
+		"(([a])+([b]))":   "([a])+([b])",
+		"([a]+[b])":       "[a]+[b]",
+		"([a])+([b])":     "([a])+([b])",
+		"[a]+[b]":         "[a]+[b]",
+		"  (upper([a])) ": "upper([a])",
+	}
+	for in, want := range tests {
+		if got := trimOuterParens(in); got != want {
+			t.Errorf("trimOuterParens(%q) = %q, want %q", in, got, want)
+		}
+	}
+}