[BUG] Service invisible to build when using profiles

Description

Profiles were added to enable us to choose which images should be included in a docker compose up.

Unfortunately, build dependencies are also filtered.

As a result, my base image - which should never be started - is either unavailable to dependent services or started alongside them.

Steps To Reproduce

Use this simple compose and try to run docker compose --profile classroom up

services:
    base:
        pull_policy: "never"
        image: "internal/base:latest"
        profiles:
            - "disabled_services"
        build:
            context: .
            tags:
                - "internal/course:base"
                - "internal/base:latest"
            dockerfile_inline: |
                FROM ghcr.io/astral-sh/uv:debian

                ENV DEBIAN_FRONTEND=noninteractive
                ENV UV_LINK_MODE=copy

                RUN apt update
                RUN apt full-upgrade -y
                RUN apt install -y --no-install-recommends curl git

                SHELL ["/bin/bash", "-c"]

                RUN curl -fsSL https://install.julialang.org | sh -s -- -y --default-channel=lts --path=/usr/local/juliaup --add-to-path=no
                ENV PATH=/usr/local/juliaup/bin:$$PATH
                RUN julia --version

                ENTRYPOINT ["/bin/bash", "-c"]
                CMD ["bash"]

    classroom:
        pull_policy: "never"
        image: "internal/classroom:latest"
        profiles:
            - "all"
            - "classroom"
        build:
            context: .
            tags:
                - "internal/course:classroom"
                - "internal/classroom:latest"
            additional_contexts:
                base: service:base
            dockerfile_inline: |
                FROM base

                # Prepare impure global venv
                RUN uv venv --seed --python 3.14 /.venv
                ENV VIRTUAL_ENV=/.venv
                ENV PATH=/.venv/bin:$$PATH

                # Install dependencies to match state right after following along with the installation guide
                RUN uv pip install jupyter
                RUN julia -e 'using Pkg; Pkg.add(["IJulia"]); Pkg.update(); Pkg.instantiate()'

                WORKDIR /course

                ENTRYPOINT ["uv", "run", "jupyter", "notebook"]
                CMD ["--help-all"]

This should result in a launch failure because base is unavailable. If you remove the profile from the base image, it will again be able to build and run the classroom image but the base image will also be launched.

When not using profiles at all and launching with docker compose up classroom, base is built as expected and only classroom is started.

I believe this is a bug but feel free to demote this to feature/change request if you think this is working as expected.

Compose Version

docker compose version
Docker Compose version v5.5.1

Docker Environment

docker info
Client: Docker Engine - Community
 Version:    29.8.0
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.37.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v5.5.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 12
  Running: 10
  Paused: 0
  Stopped: 2
 Images: 18
 Server Version: 29.8.0
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 1294c24a7da8e5a793ed378161673abe94118892
 runc version: v1.5.1-0-g8f2685a4
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.14.0-687.46.1.el9_8.x86_64
 Operating System: Rocky Linux 9.8 (Blue Onyx)
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: enough
 Name: example.com
 ID: nope
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false
 Firewall Backend: iptables
  EnableUserlandProxy: true
  UserlandProxyPath: /usr/bin/docker-proxy

Anything else?

No response

Start by reproducing the issue with the supplied docker-compose.yml and docker compose --profile classroom up; inspect how profile filtering selects services and how build dependencies from additional_contexts are resolved. Done means the classroom image can build using base without starting the profiled-out base service, while the existing no-profile behavior remains intact.