feat: M1 foundation — compose stack, FastAPI, Google OAuth, encrypted tokens

- docker-compose with Postgres 16 + slim Python API image
- FastAPI app with session middleware, health endpoint, static login page
- Google OAuth (Authlib) with email invite-list whitelist; admin role support
- User + OAuthToken models; refresh tokens encrypted at rest (Fernet)
- Alembic migrations, run automatically on container startup
- Postgres backup/restore scripts for portability between machines

scripts/restore.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+# Restores a Subfeed Postgres dump created by backup.sh into the running db container.
+# Usage:  ./scripts/restore.sh backups/subfeed-YYYYMMDD-HHMMSS.dump
+set -e
+FILE="$1"
+if [ -z "$FILE" ]; then echo "Usage: restore.sh <dumpfile>"; exit 1; fi
+if [ ! -f "$FILE" ]; then echo "Dump file not found: $FILE"; exit 1; fi
+USER_NAME="${POSTGRES_USER:-subfeed}"
+DB_NAME="${POSTGRES_DB:-subfeed}"
+docker compose exec -T db pg_restore -U "$USER_NAME" -d "$DB_NAME" --clean --if-exists < "$FILE"
+echo "Restored $FILE"