docs(plan): add implementation note about SQL migration refinements

Add a note clarifying that the SQL snippets in the plan represent the
initial design. Reference the actual shipped migrations which include
additional refinements like idempotent triggers, date validation
constraints, and improved RLS policies.

Author: BillChirico

docs/plans/2026-01-24-twelve-step-program-implementation.md

@@ -12,6 +12,21 @@
 
 ---
 
+> **Implementation Note:** The SQL snippets in this plan represent the initial design.
+> The shipped migrations in `supabase/migrations/20260124*.sql` include additional
+> refinements made during implementation:
+>
+> - `valid_month_day` CHECK constraint in `daily_readings` to validate date combinations
+> - Idempotent trigger statements (`DROP TRIGGER IF EXISTS ... CREATE TRIGGER`)
+> - `step_number`/`category` consistency CHECK in `prayers` table
+> - Numeric range CHECKs in `literature_books` and `literature_chapters`
+> - `WITH CHECK` clauses on UPDATE policies for complete RLS coverage
+> - Index on `user_prayer_history` for efficient queries
+>
+> **Always reference the actual migration files for the authoritative schema.**
+
+---
+
 ## Phase 1: Database Schema & Types
 
 ### Task 1.1: Create Database Migration for Daily Readings Tables