feat: abstracción DB multi-engine — CRUD genérico y openers para SQLite, Postgres, ClickHouse, DuckDB

Funciones Go con interfaz unificada para operaciones DB: open, close, create_table, exec, query, insert_row, insert_batch.
Openers específicos por engine. Tipo DBConfig para configuración común.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

functions/infra/db_insert_row.go

@@ -0,0 +1,54 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// DBInsertRow generates and executes a single-row INSERT from a map of
+// column→value pairs. Returns the last insert ID reported by the driver.
+// Column and table names are validated to contain only safe identifier chars.
+func DBInsertRow(db *sql.DB, table string, row map[string]any) (int64, error) {
+	if !validIdentifier.MatchString(table) {
+		return 0, fmt.Errorf("db_insert_row: invalid table name %q", table)
+	}
+	if len(row) == 0 {
+		return 0, fmt.Errorf("db_insert_row: row map must not be empty")
+	}
+
+	// Sort keys for deterministic query generation.
+	cols := make([]string, 0, len(row))
+	for col := range row {
+		if !validIdentifier.MatchString(col) {
+			return 0, fmt.Errorf("db_insert_row: invalid column name %q", col)
+		}
+		cols = append(cols, col)
+	}
+	sort.Strings(cols)
+
+	placeholders := make([]string, len(cols))
+	values := make([]any, len(cols))
+	for i, col := range cols {
+		placeholders[i] = "?"
+		values[i] = row[col]
+	}
+
+	query := fmt.Sprintf(
+		"INSERT INTO %s (%s) VALUES (%s)",
+		table,
+		strings.Join(cols, ", "),
+		strings.Join(placeholders, ", "),
+	)
+
+	result, err := db.Exec(query, values...)
+	if err != nil {
+		return 0, fmt.Errorf("db_insert_row %q: %w", table, err)
+	}
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, nil
+	}
+	return id, nil
+}