Chart rewrite for the 2.x single-server architecture: one stateless
server deployment (frontend embedded, /api served by the same process),
no PVC, single service and ingress path, optional guacd sidecar
(disabled by default), 2.x env vocabulary (TRUST_PROXY, readonly role),
probes send the public hostname as Host header.
Fixes#29: all three reported spots (PVC storageClass guard, RWX assets
PVC, frontend nginx 'backend' hostname) are removed by this rewrite.
