review fixes apr 2026 (#130)

* Multiple fixes

- refresh coordinator dedup + memory pressure wire
- middleware sse consolidation + timer leak + claim cache
- universal cache sync backfill + isDebug gate
- lazy background task race
- memory monitor stw cached + refresh() api

* fix(auth): suppress OIDC redirects on non-navigation requests

- [x] Add isNonNavigationRequest using Sec-Fetch-Mode and Accept headers
- [x] Add comprehensive TestIsNonNavigationRequest
- [x] Update ServeHTTP to 401 non-navigation and AJAX requests

Fixes #129

* feat(config): add custom CA and insecure skip verify for OIDC TLS

- [x] Add CACertPath, CACertPEM, InsecureSkipVerify to Config
- [x] Implement loadCACertPool for CA bundle loading
- [x] Update HTTPClientConfig with RootCAs and InsecureSkipVerify
- [x] Apply CA pool and skip verify to pooled HTTP clients
- [x] Enhance configKey to distinguish TLS configs
- [x] Add comprehensive ca_cert_test.go

Fixes #125

* feat(oidc): add custom CA certificate support for private OIDC providers

- [x] Add caCertPath, caCertPEM, insecureSkipVerify config options
- [x] Update traefik.yml with new OIDC client config fields
- [x] Add configuration schema descriptions for new options
- [x] Update README table and add Custom CA Certificates section

* Fix the documentation.

* test(redis): add oversized argument rejection test

- [x] Add TestRedisConn_RejectOversizedArgumentBytes
- [x] Import strings package

* Dependencies cleanup

auth_flow.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"net/http"
 	"strings"
-
-	"github.com/google/uuid"
 )
 
 // validateRedirectCount checks if redirect limit is exceeded and handles the error
@@ -77,7 +75,12 @@ func (t *TraefikOidc) defaultInitiateAuthentication(rw http.ResponseWriter, req
 		return
 	}
 
-	csrfToken := uuid.NewString()
+	csrfToken, err := newUUIDv4()
+	if err != nil {
+		t.logger.Errorf("Failed to generate CSRF token: %v", err)
+		http.Error(rw, "Failed to generate CSRF token", http.StatusInternalServerError)
+		return
+	}
 	nonce, err := generateNonce()
 	if err != nil {
 		t.logger.Errorf("Failed to generate nonce: %v", err)
@@ -334,6 +337,29 @@ func (t *TraefikOidc) isAjaxRequest(req *http.Request) bool {
 		strings.Contains(accept, "application/json")
 }
 
+// isNonNavigationRequest reports whether the request is a browser
+// sub-resource (script, image, stylesheet, fetch, serviceWorker) rather than
+// a top-level HTML navigation. Non-navigation requests MUST NOT trigger an
+// OIDC redirect flow: several sub-resource loads happening in parallel would
+// each call defaultInitiateAuthentication, each overwriting the session's
+// CSRF/nonce, breaking the eventual callback (issue #129).
+//
+// Detection prefers Sec-Fetch-Mode, which all modern browsers send
+// (Chrome/Edge/Firefox/Safari). For older or non-browser clients we fall
+// back to Accept: if Accept is present and does not list text/html, treat
+// it as a sub-resource. An empty/missing Accept is assumed to be navigation
+// (safer to redirect than 401 on an ambiguous request).
+func (t *TraefikOidc) isNonNavigationRequest(req *http.Request) bool {
+	if mode := req.Header.Get("Sec-Fetch-Mode"); mode != "" {
+		return mode != "navigate"
+	}
+	accept := req.Header.Get("Accept")
+	if accept == "" || accept == "*/*" {
+		return false
+	}
+	return !strings.Contains(accept, "text/html")
+}
+
 // isRefreshTokenExpired checks if refresh token is likely expired (older than 6 hours)
 func (t *TraefikOidc) isRefreshTokenExpired(session *SessionData) bool {
 	// This is a heuristic check - actual implementation would depend on