Three root causes addressed: 1. Added <base href="/"> to index.html so all relative asset paths (css/app.css, js/*.js) resolve from the root regardless of the current SPA route. Without this, /instance/117 requested /instance/css/app.css, which hit the SPA fallback and returned HTML; helmet's nosniff then refused it as a stylesheet. 2. Removed upgrade-insecure-requests from the CSP (useDefaults: false). This directive told browsers to upgrade HTTP→HTTPS for every asset request, breaking all resource loading on HTTP-only deployments. 3. Changed script-src-attr from 'none' to 'unsafe-inline' to allow the inline onclick handlers used throughout the UI. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
7.3 KiB
7.3 KiB