Phase 4 cleanup & polish: param migration seeds, gnexus-ui-kit LoginPage styles, single .env ...

- Replace raw string interpolation in migration with $tb->prepare() + execute()

- Remove all var(--color-*) from LoginPage.vue in favor of gnexus-ui-kit utility classes

- Unify .env: single server/.env, remove server/SHServ/.env override, update config.php

- Update auth-fix-plan.md: mark Phase 4 tasks complete

Add server/dist build to repository for zero-dependency prod deploy

Integrate Vue webclient into server: serve SPA from /, remove proxy.php, update auth redirects

Fix framework bugs found during OTA testing ...

- DevTools: guard against empty sql_queries array before accessing last index
- RouterImplementation: skip empty route var names in POST routing
- CallControl: skip empty route var names when building action params
- Update .gitignore to exclude Cache, Logs, and firmwares dirs

Phase 1: Security Foundation (auth, SQLi, secrets, hashing, tokens, cookies)

Added .gitignore