chore(showroom): bump nookbag to v0.3.6 and wetty to v2.7.6

[andrew-jones]

Update the default nookbag UI bundle and wetty terminal image versions across both the OCP and VM showroom roles to pick up the latest releases.

Changes

• Bump wetty image from v2.5 to v2.7.6 in ocp4_workload_showroom
• Bump wetty image from v2.7.4 to v2.7.6 in vm_workload_showroom
• Bump nookbag zero-touch bundle from v0.3.4 to v0.3.6 in both roles

Nookbag changes (v0.3.4 → v0.3.6)

• rhpds/nookbag#59 — Replace floating view switcher with right-edge popout and modernize UI
• rhpds/nookbag#60 — Remove padding and use transparent background for terminal iframes

Wetty image changes (v2.5 → v2.7.6)

showroom-images (container build):

• rhpds/showroom-images#56 — Build wetty from source using andrew-jones/wetty fork
• rhpds/showroom-images#57 — Fix wetty OCP entrypoint and add postMessage execute-listener
• rhpds/showroom-images#58 — Simplify execute-listener to target wetty-only with debug logging
• rhpds/showroom-images#60 — Pin wetty build to v2.7.4 release tag
• rhpds/showroom-images#61 — Bump wetty version to v2.7.5
• rhpds/showroom-images#62 — Bump wetty version to v2.7.6

andrew-jones/wetty (upstream fork):

• andrew-jones/wetty#1 — Prevent socket disconnects in background tabs
• andrew-jones/wetty#2 — Harden SSH and WebSocket resilience against idle drops and browser throttling
• andrew-jones/wetty#3 — Add terminal color theme support via CLI and URL query param