Rebrand repository from "Re:Link" to "Startover" across the codebase. Updates include package names and scopes (@relink/* -> @startover/*), import paths, Next.js transpile settings, vitest name, UI text and docs, Dockerfile and CI/workflow names, deploy scripts and repo paths, and example/production env values. Also add auth-related env vars, an apps/web .env symlink, and small formatting/typing cleanups in several TSX/TS files and tests to accommodate the rename.