fix(docs): remove outdated DB_README and atomic collection creation SQL file

DB_README.md

@@ -1,116 +0,0 @@
-# Database & Backend Notes
-
-This document is the operational source of truth for database setup and backend contracts used by the app.
-
-## Stack
-
-- Supabase Postgres
-- Supabase Auth
-- Supabase Storage
-- Supabase RPC functions
-
-## Scope
-
-This file intentionally stays concise. Do not paste full raw data-dictionary exports here.
-
-If you need snapshots, store them separately (for example in a local `db_exports/` folder) and summarize only key outcomes in this file.
-
-## Environments
-
-Document environment endpoints and ownership:
-
-- Development: TBD
-- Staging: TBD
-- Production: TBD
-
-## Core App Tables
-
-Keep this section focused on app-owned tables (not full Supabase system schemas).
-
-- `collections`
-- `collection_members`
-- `hotwheels`
-- `global_cars`
-- `car_votes`
-- `car_reports`
-
-## Key RPC Functions
-
-- `get_collection_counts`
-- `get_collection_members`
-- `get_user_id_by_email`
-- `remove_collection_member`
-- `create_collection_with_owner` (atomic create path)
-
-## Atomic Collection Creation
-
-App code now prefers a transactional RPC for collection creation:
-
-- App integration: `CollectionService.create()`
-- Migration script: `db/atomic_create_collection_with_owner.sql`
-
-### Apply
-
-Run the script in Supabase SQL Editor:
-
-- `db/atomic_create_collection_with_owner.sql`
-
-## RLS Expectations
-
-For each core table, document:
-
-- who can `select`
-- who can `insert`
-- who can `update`
-- who can `delete`
-- special policy conditions
-
-Status: TBD
-
-## Storage
-
-- Bucket: `car-images` (private)
-- Access model: signed URLs from app/backend
-- Ownership path pattern: `{auth.uid()}/{entry.id}.jpg`
-
-## Migration Workflow
-
-1. Write SQL migration in repository (`db/` or migration folder).
-2. Validate in development.
-3. Verify RLS impact.
-4. Promote to staging.
-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:
-
-- [ ] Migration SQL reviewed
-- [ ] RLS policy impact checked
-- [ ] RPC grant/permissions verified
-- [ ] Rollback strategy identified
-- [ ] App compatibility validated (`flutter analyze`, tests, smoke flows)
-
-## Known Risks / Notes
-
-- Keep app and DB changes synchronized when changing RPC signatures.
-- Favor DB-side transactional functions for multi-step write operations.
-- Avoid exposing backend internals in user-facing error messages.
-
-## References
-
-- App service integration: `lib/services/collection_service.dart`
-- Atomic RPC migration: `db/atomic_create_collection_with_owner.sql`
-- Security process: `SECURITY.md`

db/atomic_create_collection_with_owner.sql

@@ -1,48 +0,0 @@
--- Atomic collection creation + owner membership insert
--- Run this in Supabase SQL Editor.
-
-create or replace function public.create_collection_with_owner(
-  p_name text,
-  p_description text default null
-)
-returns public.collections
-language plpgsql
-security definer
-set search_path = public
-as $$
-declare
-  v_user_id uuid := auth.uid();
-  v_collection public.collections;
-begin
-  if v_user_id is null then
-    raise exception 'Not authenticated';
-  end if;
-
-  insert into public.collections (
-    name,
-    owner_id,
-    description
-  )
-  values (
-    p_name,
-    v_user_id,
-    nullif(trim(p_description), '')
-  )
-  returning * into v_collection;
-
-  insert into public.collection_members (
-    collection_id,
-    user_id,
-    role
-  )
-  values (
-    v_collection.id,
-    v_user_id,
-    'owner'
-  );
-
-  return v_collection;
-end;
-$$;
-
-grant execute on function public.create_collection_with_owner(text, text) to authenticated;

db/export_schema.sql

@@ -1,4 +1,3 @@
--- 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)