fix(schema): replace dead stripe columns with provider_id columns on products

Dropped stripe_product_id and stripe_price_id (added in 20260201, superseded
in 20260207 by the generic payment_provider column — but never cleaned up).
All rows were NULL and no application code referenced them on products.

Added the missing provider_product_id and provider_price_id columns that the
createProduct / updateProduct server actions have always tried to write. Without
them, any admin form product creation returned PGRST204 "column does not exist".
These columns are provider-agnostic: Stripe stores real IDs, manual provider
stores a local mock ID, PayPal would store its equivalent.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: guillermoscript

supabase/migrations/20260518150000_drop_dead_stripe_columns_from_products.sql

@@ -0,0 +1,15 @@
+-- Drop dead stripe_product_id and stripe_price_id columns from products.
+--
+-- These were the original Stripe-specific columns added in
+-- 20260201145244_admin_dashboard_setup.sql. Migration
+-- 20260207190849_add_payment_provider_to_products.sql replaced them with
+-- the generic provider_product_id / provider_price_id columns that support
+-- Stripe, PayPal, manual, and any future provider.
+--
+-- All rows have NULL values. No application code references these columns
+-- on the products table (the identically-named columns on the plans table
+-- are separate and remain untouched).
+
+ALTER TABLE public.products
+  DROP COLUMN IF EXISTS stripe_product_id,
+  DROP COLUMN IF EXISTS stripe_price_id;

supabase/migrations/20260518150001_add_provider_id_columns_to_products.sql

@@ -0,0 +1,15 @@
+-- Add provider_product_id and provider_price_id to products.
+--
+-- Migration 20260207190849 added the payment_provider column but never added
+-- the two ID columns the createProduct / updateProduct server actions write.
+-- Without them, any INSERT or UPDATE that includes these fields returns
+-- PGRST204 ("column does not exist"), making product creation from the admin
+-- form completely broken.
+--
+-- These replace the old stripe_product_id / stripe_price_id columns (dropped
+-- in 20260518150000) with a provider-agnostic pair that works for Stripe,
+-- PayPal, and manual (where they hold a local mock ID).
+
+ALTER TABLE public.products
+  ADD COLUMN IF NOT EXISTS provider_product_id TEXT,
+  ADD COLUMN IF NOT EXISTS provider_price_id   TEXT;