White-label: title/logo now driven by conf (closes #45)

<title>, the navbar brand text, and the logo were all hardcoded
"Proxy - Theta 42"/"Dynamic Proxy". New conf.name/conf.logo keys
(defaults matching current text/asset) thread through the existing
values object pattern in routes/render.js and routes/docs.js, and
top.ejs now renders <%- name %>/<%- logo %> for the title and a new
navbar logo image.

Footer (copyright, theta42.com link, GitHub/license links) and the
existing favicon.svg are left as-is -- open-source attribution and a
distinct, already-working icon asset, not deployment branding.

secrets.js.example

@@ -18,6 +18,9 @@
 // theta-env orchestrator (setup.sh) and ignored by the app.
 
 module.exports = {
+    name: 'Dynamic Proxy',                // shown in the UI
+    logo: '/static/img/theta42.svg',      // nav image; point at your own file under public/ to white-label
+
     // OpenID Connect — point at your SSO Manager. Issuer + authorization/
     // endSession are browser-facing URLs; token/userinfo can be the internal
     // URL if the SSO is on the same docker network (avoids a TLS hairpin).