docs(db): add reproducible public schema export query pack

DB_README.md

@@ -82,6 +82,17 @@ Status: TBD
 5. Promote to production.
 6. Record change summary in this document.
 
+## Reproducible Schema Snapshot
+
+- Query pack: `db/export_schema.sql`
+- Goal: produce repeatable app-focused schema snapshots without bloating docs
+
+Suggested usage:
+
+1. Run `db/export_schema.sql` in Supabase SQL Editor.
+2. Export result sets (CSV/JSON) and store externally (for example `db_exports/` in local/private ops repo).
+3. Summarize only key changes in this `DB_README.md`.
+
 ## Operational Checklist
 
 Before deploy:

db/export_schema.sql

@@ -0,0 +1,115 @@
+-- Reproducible schema export query pack (app-focused)
+-- Run in Supabase SQL Editor or psql and export results as CSV/JSON.
+
+-- 1) App tables and columns (public only)
+select
+  c.table_name,
+  c.ordinal_position,
+  c.column_name,
+  c.data_type,
+  c.udt_name,
+  c.is_nullable,
+  c.column_default
+from information_schema.columns c
+join information_schema.tables t
+  on t.table_schema = c.table_schema
+ and t.table_name = c.table_name
+where c.table_schema = 'public'
+  and t.table_type = 'BASE TABLE'
+order by c.table_name, c.ordinal_position;
+
+-- 2) Constraints
+select
+  rel.relname as table_name,
+  con.conname as constraint_name,
+  case con.contype
+    when 'p' then 'PRIMARY KEY'
+    when 'u' then 'UNIQUE'
+    when 'f' then 'FOREIGN KEY'
+    when 'c' then 'CHECK'
+    else con.contype::text
+  end as constraint_type,
+  pg_get_constraintdef(con.oid, true) as definition
+from pg_constraint con
+join pg_class rel on rel.oid = con.conrelid
+join pg_namespace n on n.oid = rel.relnamespace
+where n.nspname = 'public'
+order by rel.relname, con.conname;
+
+-- 3) Indexes
+select
+  tablename,
+  indexname,
+  indexdef
+from pg_indexes
+where schemaname = 'public'
+order by tablename, indexname;
+
+-- 4) Views
+select
+  c.relname as view_name,
+  case c.relkind when 'v' then 'VIEW' when 'm' then 'MATERIALIZED VIEW' end as view_type,
+  pg_get_viewdef(c.oid, true) as definition
+from pg_class c
+join pg_namespace n on n.oid = c.relnamespace
+where n.nspname = 'public'
+  and c.relkind in ('v', 'm')
+order by c.relname;
+
+-- 5) Functions / Procedures
+select
+  p.proname as routine_name,
+  case p.prokind when 'p' then 'PROCEDURE' else 'FUNCTION' end as routine_type,
+  l.lanname as language,
+  pg_get_function_identity_arguments(p.oid) as args,
+  pg_get_functiondef(p.oid) as definition
+from pg_proc p
+join pg_namespace n on n.oid = p.pronamespace
+join pg_language l on l.oid = p.prolang
+where n.nspname = 'public'
+order by p.proname;
+
+-- 6) Triggers
+select
+  c.relname as table_name,
+  t.tgname as trigger_name,
+  pg_get_triggerdef(t.oid, true) as definition
+from pg_trigger t
+join pg_class c on c.oid = t.tgrelid
+join pg_namespace n on n.oid = c.relnamespace
+where n.nspname = 'public'
+  and not t.tgisinternal
+order by c.relname, t.tgname;
+
+-- 7) RLS status
+select
+  c.relname as table_name,
+  c.relrowsecurity as rls_enabled,
+  c.relforcerowsecurity as rls_forced
+from pg_class c
+join pg_namespace n on n.oid = c.relnamespace
+where n.nspname = 'public'
+  and c.relkind = 'r'
+order by c.relname;
+
+-- 8) RLS policies
+select
+  tablename,
+  policyname,
+  permissive,
+  roles,
+  cmd,
+  qual,
+  with_check
+from pg_policies
+where schemaname = 'public'
+order by tablename, policyname;
+
+-- 9) Grants (tables)
+select
+  table_name,
+  privilege_type,
+  grantee
+from information_schema.role_table_grants
+where table_schema = 'public'
+order by table_name, grantee, privilege_type;