docs: record DB migrations for admin panel v2

supabase/migrations/001_admin_panel_v2.sql

@@ -0,0 +1,27 @@
+-- Migration: Admin Panel v2
+-- Run manually in Supabase SQL Editor (Dashboard → SQL Editor → New Query)
+
+-- 1. Settings table for configurable pricing
+CREATE TABLE settings (
+  key TEXT PRIMARY KEY,
+  value TEXT NOT NULL,
+  updated_at TIMESTAMPTZ DEFAULT now()
+);
+
+INSERT INTO settings (key, value) VALUES
+  ('price_200', '2000'),
+  ('price_300', '3000');
+
+ALTER TABLE settings ENABLE ROW LEVEL SECURITY;
+
+CREATE POLICY "Anyone can read settings"
+  ON settings FOR SELECT USING (true);
+
+CREATE POLICY "Auth users can update settings"
+  ON settings FOR UPDATE USING (auth.role() = 'authenticated');
+
+-- 2. New contact fields on orders
+ALTER TABLE orders
+  ADD COLUMN IF NOT EXISTS telegram_username TEXT,
+  ADD COLUMN IF NOT EXISTS max_username TEXT,
+  ADD COLUMN IF NOT EXISTS address TEXT;