Public web-only release: SvxPortal front-end + auth backend, install templates and INSTALL.md

Stripped from the internal repo: per-box deploy trees, Go services (nodelist/astmeta/proxy/svxdr),
deploy/sync scripts and all secrets. Config templates for nginx, PHP-FPM, Redis and tmpfiles
live in install/ with CHANGEME placeholders.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,11 @@
+# Secrets — never commit
+auth/config.php
+
+# Backups / editor cruft
+*.bak
+*.bak.*
+*~
+*.orig
+*.save
+*.swp
+*.bak-*