chore: sentry and nextjs major bumps (#633)

* chore: remove nextjs-config

* build fix

* sentry update

* nextjs update

* feature flags doc

* update readme

* explicit nextjs env vars + remove feature-unrelated things and obsolete vars from config

* full config removal

* remove force-dynamic from pages

* compile fix

* restore claude-deleted tests

* no sentry backward compat

* better .env.example

* AUTHENTIK_REFRESH_TOKEN_URL not so required

* accommodate auth system to requiredLogin feature

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

www/instrumentation.ts

@@ -0,0 +1,9 @@
+export async function register() {
+  if (process.env.NEXT_RUNTIME === "nodejs") {
+    await import("./sentry.server.config");
+  }
+
+  if (process.env.NEXT_RUNTIME === "edge") {
+    await import("./sentry.edge.config");
+  }
+}