Add Dockerfile (cpu/cuda/vulkan), entrypoint, docs, and a GHCR build/release workflow (#15)

* Add Dockerfile (cpu/cuda), entrypoint, docs, and a GHCR release workflow

Multi-stage Dockerfile with cpu and cuda targets, built from the
existing build scripts' cmake invocations. The CUDA target documents
and applies the two docker-build-specific gotchas we hit running this
in production: CMAKE_CUDA_ARCHITECTURES needs an explicit override for
GPUs older than this project's own default arch list when building
without GPU device access, and the CUDA driver stub library needs an
explicit -L/-lcuda at link time since ggml's VMM pool allocator needs
driver-API symbols that aren't present without a real driver. Also
installs make/pkg-config/libopenblas-dev (CPU build) and libgomp1
(CUDA runtime), and copies the ggml shared libraries alongside the
binaries with LD_LIBRARY_PATH set, since the binaries' baked-in RPATH
points at the build-tree location that doesn't exist in the final
stage.

Adds a GitHub Actions workflow that builds both variants on every
push to master and version tag, publishing to
ghcr.io/serveurpersocom/qwentts.cpp, and validates the build (without
pushing) on PRs that touch the Docker files.

Verified end-to-end on a real GTX 1070 (Pascal): both cpu and cuda
targets build clean, run, and produce valid synthesized WAV output
through tts-server's HTTP API.

* Dockerfile: add a vulkan build target (AMD/Intel GPUs)

Uses the LunarG Vulkan SDK apt repo for glslc (ggml-vulkan's shader
compiler), which Ubuntu 22.04's own repos don't package. Runtime image
ships Mesa's Vulkan drivers; NVIDIA users should prefer :cuda instead,
since NVIDIA's Vulkan ICD isn't bundled.

* docker workflow: bump actions to latest majors (checkout v7, buildx v4, login v4, build-push v7)

* Support Pascal (sm_61) in the default CUDA architecture list

Adds 61-real to CMAKE_CUDA_ARCHITECTURES' default so Pascal cards
(GTX 10-series etc.) work without an explicit override -- including
in the Docker cuda target, where docker build has no GPU device to
autodetect against in the first place. Real-only (no virtual/PTX):
Pascal is now the oldest supported card, so it doesn't need to seed
forward JIT compatibility for anything older the way the 75-virtual
entry does for 7.5+.

Verified end-to-end on a real GTX 1070 (sm_61): built the cuda Docker
target with no --build-arg override, ran it with --gpus all, and
confirmed via container logs that the GPU loaded the model and served
a real synthesis request producing valid WAV output.

Adjusts the Dockerfile comments and docs/DOCKER.md accordingly.

* docker: pass through --max-prefill-tokens, add ref_text voice cloning

- entrypoint.sh: forward MAX_PREFILL_TOKENS to --max-prefill-tokens,
  matching the existing optional-flag passthrough pattern
- entrypoint.sh: a same-stem .txt next to a voice's .wav now supplies
  ref_text, enabling ICL clone mode instead of the x_vector_only
  fallback used when no transcript is given
- switch voice registration's JSON construction from raw printf to jq
  for safe escaping of arbitrary transcript text; base64 payloads go
  through jq's --rawfile (not --arg) since large files blow past
  ARG_MAX as a command-line argument
- add jq to all three runtime image stages (cpu/cuda/vulkan) for the
  above
- docs/DOCKER.md: document both additions

Verified end-to-end on a CPU build: both the ref_text and no-ref_text
registration paths log correctly (ref_text=yes / ref_text=no) and
/health responds after voice registration completes.

* docker: opt-in fatal worst-case warmup synthesis

ggml_backend_sched grows its compute buffer to fit the largest graph
it has ever built and never shrinks it back, so VRAM use can ratchet
up the first time a long reply arrives on live traffic. This adds an
opt-in startup warmup: when WARMUP_VOICE is set, entrypoint.sh runs
one real synthesis capped at WARMUP_MAX_NEW_TOKENS (default 750)
frames after voice registration, forcing that worst-case decode/
codec-decode buffer growth to happen at startup instead of mid-request.
Complements --max-prefill-tokens, which only covers the input side.

Off by default (WARMUP_VOICE unset skips it entirely, matching every
other optional flag in this entrypoint), and fatal on failure: if the
warmup synthesis fails (most likely OOM), the container kills the
server and exits non-zero rather than come up healthy and fail
unpredictably later -- a deployment that can't afford its own
configured worst case should know that at startup, not on a live
request.

Verified on a CPU build: warmup runs after voice registration, hits
the configured frame cap exactly, and the container stays healthy.

---------

Co-authored-by: Gary <gitea@gerasch.dev>

CMakeLists.txt

@@ -46,14 +46,17 @@ if(NOT MSVC AND NOT GGML_SYCL)
     add_compile_definitions(_FORTIFY_SOURCE=2)
 endif()
 
-# CUDA architectures: cover Turing to Blackwell for distributed binaries.
+# CUDA architectures: cover Pascal to Blackwell for distributed binaries.
+# Pascal (61-real) is SASS-only, no virtual/PTX entry: it's the oldest
+# supported card and doesn't need to seed forward JIT compat for anything
+# older, unlike the 75-virtual baseline which does that for 7.5+.
 # Users can override with -DCMAKE_CUDA_ARCHITECTURES=native for local builds.
 if(NOT DEFINED CMAKE_CUDA_ARCHITECTURES)
     find_package(CUDAToolkit QUIET)
     if(CUDAToolkit_FOUND AND CUDAToolkit_VERSION VERSION_GREATER_EQUAL "12.8")
-        set(CMAKE_CUDA_ARCHITECTURES "75-virtual;80-virtual;86-real;89-real;120a-real;121a-real")
+        set(CMAKE_CUDA_ARCHITECTURES "61-real;75-virtual;80-virtual;86-real;89-real;120a-real;121a-real")
     else()
-        set(CMAKE_CUDA_ARCHITECTURES "75-virtual;80-virtual;86-real;89-real")
+        set(CMAKE_CUDA_ARCHITECTURES "61-real;75-virtual;80-virtual;86-real;89-real")
     endif()
 endif()