vibevoice + chatterbox: fix build refs (full 40-char SHA + chatterbox dockerfile path)

Both deploys failed against irv-ml1 today with upstream-changed-on-us
errors:

* vibevoice: VIBEVOICE_SHA=7614c469a145 (12-char short) made docker
  buildx report "repository does not contain ref 7614c469a145" — same
  commit IS still HEAD of main, but buildx's git source resolver
  doesn't accept short hashes even when unambiguous. Now full 40-char.

* chatterbox: dockerfile: docker/Dockerfile.gpu — devnen restructured
  the repo to put Dockerfiles at root, renamed by CUDA version
  (Dockerfile.cu128, .cpu, .rocm). Switched to Dockerfile.cu128 (GPU
  build for CUDA 12.8 toolkit; works on irv-ml1's 595.58.03 driver).
  Also pinned CHATTERBOX_SHA to a full 40-char SHA instead of `main`
  so future upstream churn doesn't break the deploy without warning.

Live host .env files patched directly (the playbook only seeds .env
when absent, so canonical edits don't propagate to existing installs).

stacks/chatterbox/compose.yaml

@@ -24,7 +24,12 @@ services:
     image: local/chatterbox:${CHATTERBOX_TAG}
     build:
       context: https://github.com/devnen/Chatterbox-TTS-Server.git#${CHATTERBOX_SHA}
-      dockerfile: docker/Dockerfile.gpu
+      # Upstream moved Dockerfiles from docker/ to repo root and renamed
+      # them by CUDA version (Dockerfile.cu128, .cpu, .rocm). The old
+      # `docker/Dockerfile.gpu` is gone. cu128 is the GPU build for
+      # CUDA 12.8 — fits irv-ml1's 595.58.03 driver (CUDA 13.2 capable,
+      # backward-compatible to 12.8 toolkit-built images).
+      dockerfile: Dockerfile.cu128
     container_name: chatterbox
     restart: unless-stopped
     runtime: nvidia