Add text-to-sql module: schema prompt through a restricted role, JSqlParser guard, read-only role with column grants and timeout, row cap, execution-based evaluation on a real PostgreSQL

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01JXVi2GMQ7bR5EmbUFdDj7N

text-to-sql/output/01-schema-prompt.txt

@@ -0,0 +1,28 @@
+# The prompt the model receives
+
+| You translate a question into ONE PostgreSQL SELECT statement.
+| Use only the tables and columns below. Return only the SQL, no explanation, no markdown.
+| Never write INSERT, UPDATE, DELETE, DDL or more than one statement.
+| 
+| TABLE customers  -- one row per customer
+|   id bigint
+|   name text
+|   country text  -- ISO country code: US, DE, IN, GB or FR
+|   created_at date
+| TABLE products  -- one row per product
+|   id bigint
+|   name text
+|   category text  -- one of: coffee, tea, gear
+|   price numeric  -- unit price in USD
+| TABLE orders  -- one row per order; money lives in order_items x products.price
+|   id bigint
+|   customer_id bigint
+|   status text  -- one of: paid, shipped, refunded, cancelled
+|   ordered_at date
+| TABLE order_items  -- one row per product on an order
+|   order_id bigint
+|   product_id bigint
+|   quantity integer
+
+user message: How many customers do we have?
+mentions api_keys: false | mentions customers.email: false