Two improvements to the OpenAPI spec plumbing:

1. openapi.yaml is now the single source of truth. A new CMake custom
   command runs gen_openapi_yaml_h.py to generate openapi_yaml.h at
   build time (rebuilds only when openapi.yaml changes). routes_docs.cpp
   includes the generated header instead of embedding a 1500-line copy.

2. A new validation gate (validate_openapi.py) runs as a pre-build step
   and fails the build if openapi.yaml paths do not match the routes
   registered in routes_openai.cpp, routes_sdapi.cpp, and
   routes_sdcpp.cpp. Parameterised httplib regex paths are mapped to
   their OpenAPI path template equivalents before comparison.

https://claude.ai/code/session_01UWEVrPisViQsb7DQm1eGn4

Adds .github/workflows/docker-ci.yml which triggers on push to any
branch descended from the `docker` base branch (determined via
git merge-base ancestry check).

Flow per push:
1. check-ancestry — fast gate; skips all subsequent jobs if the branch
   is not descended from `docker`
2. build-linux-cpu + build-linux-vulkan — run in parallel; each
   installs pyyaml, runs validate_openapi.py explicitly, then builds
   with cmake (cmake also re-runs the validator as a pre-build step)
3. build-and-push-docker — gated on both CI jobs passing; builds
   Dockerfile.vulkan and pushes to ghcr.io/mihard/stable-diffusion.cpp
   tagged <sanitized-branch>-<short-sha>

https://claude.ai/code/session_01QA3cwbaLkeP2sBbxAFKQFj

- Dockerfile.vulkan: add python3 + python3-yaml to build stage so the
  cmake pre-build step (validate_openapi.py) can run inside the container
- docker-ci.yml: drop build-linux-vulkan job — Vulkan compilation is
  already validated by the Docker build itself (same as upstream CI)
  Update build-and-push-docker needs accordingly

https://claude.ai/code/session_01QA3cwbaLkeP2sBbxAFKQFj

- docker-ci.yml: change IMAGE_NAME to <repo>/vulkan so images are
  published as ghcr.io/mihard/stable-diffusion.cpp/vulkan:<branch>-<sha>
- cleanup-ghcr.yml: weekly scheduled job (Sundays 03:00 UTC) using
  snok/container-retention-policy to delete vulkan image versions
  older than 30 days; also wired to workflow_dispatch for manual runs

https://claude.ai/code/session_01QA3cwbaLkeP2sBbxAFKQFj

…endpoints

Adds standalone image upscaling to both API surfaces:

- POST /sdapi/v1/extra-single-image (synchronous, A1111-compatible)
  Accepts image + upscaler_1/upscaler_2 + scale/target dims. Returns
  {"image": "<base64-png>", "html_info": ""}.

- POST /sdcpp/v1/upscale (async, native sdcpp API)
  Queues an upscale job, polled via GET /sdcpp/v1/jobs/{id}.

Shared upscale logic (perform_upscale) handles:
  - Built-in upscalers: None (passthrough), Lanczos (CatmullRom filter),
    Nearest (Box filter) via new resize_sd_image() in media_io
  - Model-backed upscalers: new_upscaler_ctx/upscale from hires_upscalers_dir
  - Optional two-upscaler pixel blending (upscaler_2_visibility)
  - ESRGAN output → exact target size resize when dims differ

Also adds ExtraSingleImageRequest, ExtraSingleImageResponse, and
UpscaleRequest schemas to openapi.yaml (19 routes validated).

https://claude.ai/code/session_01WVK99Jp6uLuZwnXpydhK3G