Pin the body cap's order in every page route group (closes #93)

A route test now posts an oversized body with no session or CSRF
token to each page route group, /settings included, and requires 413
with no CSRF cookie. Before, only the login form pinned the cap ahead
of CSRF; reordering the /settings, /hooks or /hook groups failed
nothing.

The MaxBodySize doc comment says other methods pass uncapped on
purpose, and the middleware test comment names the helper it
describes. The three router helpers in the server tests build the
Server through New, on a lifecycle that is never started, instead of
setting its fields by hand. The README already described the cap's
position correctly.

Model: opus-5-5

internal/server/export_test.go

@@ -1,13 +1,16 @@
 package server
 
 import (
-	"log/slog"
 	"net/http"
+	"testing"
 
 	"github.com/getsentry/sentry-go"
 	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx/fxtest"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/logger"
 	"sneak.berlin/go/webhooker/internal/middleware"
 )
 
@@ -34,23 +37,45 @@ func SentryClientOptionsForTest(
 	return sentryClientOptions(dsn, release)
 }
 
+// newServerForTest builds a Server through New, as the application
+// does, on a lifecycle that is never started: the hooks New adds to
+// it never run, so nothing listens.
+func newServerForTest(
+	t *testing.T,
+	log *logger.Logger,
+	cfg *config.Config,
+	mw *middleware.Middleware,
+	h *handlers.Handlers,
+) *Server {
+	t.Helper()
+
+	s, err := New(fxtest.NewLifecycle(t), ServerParams{
+		Logger:     log,
+		Config:     cfg,
+		Middleware: mw,
+		Handlers:   h,
+	})
+	require.NoError(t, err)
+
+	return s
+}
+
 // NewRouterForTest builds the real route tree via SetupRoutes with
-// the supplied middleware and handlers, bypassing the fx lifecycle
-// and the HTTP listener. Tests use it so that route-group middleware
-// registration order is exercised exactly as it ships, rather than
-// against a hand-rebuilt chain that could drift from routes.go.
+// the supplied middleware and handlers, on a Server from New whose
+// lifecycle is never started, so no HTTP listener runs. Tests use it
+// so that route-group middleware registration order is exercised
+// exactly as it ships, rather than against a hand-rebuilt chain that
+// could drift from routes.go.
 func NewRouterForTest(
-	log *slog.Logger,
+	t *testing.T,
+	log *logger.Logger,
 	cfg *config.Config,
 	mw *middleware.Middleware,
 	h *handlers.Handlers,
 ) http.Handler {
-	s := &Server{
-		log:    log,
-		mw:     mw,
-		h:      h,
-		params: ServerParams{Config: cfg},
-	}
+	t.Helper()
+
+	s := newServerForTest(t, log, cfg, mw, h)
 	s.SetupRoutes()
 
 	return s.router
@@ -83,19 +108,17 @@ const ProbePattern = "/probe"
 // option and the recoverer registered outside it is the thing a test
 // has to be able to pin.
 func NewRouterWithProbeForTest(
-	log *slog.Logger,
+	t *testing.T,
+	log *logger.Logger,
 	cfg *config.Config,
 	mw *middleware.Middleware,
 	h *handlers.Handlers,
 	sentryEnabled bool,
 	probe http.HandlerFunc,
 ) http.Handler {
-	s := &Server{
-		log:    log,
-		mw:     mw,
-		h:      h,
-		params: ServerParams{Config: cfg},
-	}
+	t.Helper()
+
+	s := newServerForTest(t, log, cfg, mw, h)
 	s.sentryEnabled.Store(sentryEnabled)
 	s.SetupRoutes()
 	s.router.Handle(ProbePattern, probe)
@@ -113,19 +136,17 @@ const PageProbePattern = "/pages/probe"
 // it, so the probe runs behind that group's own middleware exactly as
 // the group's real routes do.
 func NewRouterWithPageProbeForTest(
-	log *slog.Logger,
+	t *testing.T,
+	log *logger.Logger,
 	cfg *config.Config,
 	mw *middleware.Middleware,
 	h *handlers.Handlers,
 	sentryEnabled bool,
 	probe http.HandlerFunc,
 ) http.Handler {
-	s := &Server{
-		log:    log,
-		mw:     mw,
-		h:      h,
-		params: ServerParams{Config: cfg},
-	}
+	t.Helper()
+
+	s := newServerForTest(t, log, cfg, mw, h)
 	s.sentryEnabled.Store(sentryEnabled)
 	s.SetupRoutes()