Rename project from Re:Link to Startover

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.

Dockerfile

@@ -1,5 +1,5 @@
 # ============================================
-# Re:Link Turborepo Multi-stage Dockerfile
+# Startover Turborepo Multi-stage Dockerfile
 # Usage: docker build --build-arg APP_NAME=web .
 # ============================================
 
@@ -32,7 +32,7 @@ COPY . .
 
 # Generate Prisma client & build
 RUN cd packages/database && npx prisma generate
-RUN pnpm turbo run build --filter=@relink/${APP_NAME}
+RUN pnpm turbo run build --filter=@startover/${APP_NAME}
 
 # Ensure public directories exist for COPY
 RUN mkdir -p /app/apps/${APP_NAME}/public