Implement dual SQLite/Supabase backend with runtime flag

[Copilot]

Implements the dual-backend database architecture outlined in the migration plan. The site can run using either SQLite or Supabase (PostgreSQL) based on the DB_BACKEND environment variable, defaulting to sqlite so existing tests and local development are unchanged.

Architecture

• db_interface.ts — TypeScript interface declaring all 43 database functions as async
• db_sqlite.ts — SQLite implementation extracted from original db.ts, wrapped in async
• db_supabase.ts — Supabase implementation using @supabase/supabase-js with query builder, foreign key joins, and RPC calls for atomic operations
• db.ts — Thin runtime dispatcher that selects the backend based on DB_BACKEND env var and re-exports all functions

Changes

• All 6 caller files (index.ts, routes/auth.ts, routes/websites.ts, routes/git_websites.ts, routes/friends.ts, routes/messages.ts) updated to await all DB calls
• PostgreSQL schema migration (supabase/migrations/001_initial.sql) with 10 tables, citext columns, and indexes
• 5 PostgreSQL RPC functions (supabase/migrations/002_rpc_functions.sql) for atomic operations: accept_friend_request, remove_friend, set_website_tags, get_unread_counts, get_all_tags_with_counts
• Added @supabase/supabase-js dependency
• .env.example documenting DB_BACKEND, DB_PATH, SUPABASE_URL, SUPABASE_SERVICE_ROLE_KEY
• Updated plan in plans/supabase_migration.md with all steps marked as completed

Testing

• All 182 existing tests pass unchanged against the SQLite backend
• CodeQL security scan: 0 alerts
• No dependency vulnerabilities

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[lyncmi07]

@copilot complete the plan

[Copilot]

@copilot complete the plan

Done in cbe6ea1. All 10 plan steps implemented:

• db_interface.ts — 43-function async interface
• db_sqlite.ts — extracted SQLite implementation
• db_supabase.ts — full Supabase implementation with joins, RPC calls, and boolean normalization
• db.ts — runtime dispatcher via DB_BACKEND env var (defaults to sqlite)
• All 6 caller files updated with await
• supabase/migrations/001_initial.sql — PostgreSQL schema (10 tables, indexes)
• supabase/migrations/002_rpc_functions.sql — 5 RPC functions for atomic operations
• .env.example — documents all env vars

All 182 existing tests pass unchanged against the SQLite backend.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• example.com
  • Triggering command: /home/REDACTED/.bun/bin/bun bun run index.ts (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)