[clue]

This changeset updates the build to use Docker instead of requiring a local PHP and Composer installation. make now builds the website from the same Dockerfile the Docker Compose setup from #147 already uses and exports only the generated site into build/, so what gets deployed is exactly what the container serves.

This also means CI no longer needs to set up PHP. The HTML diff job still builds the base branch with that revision's own make, which now uses the PHP version that comes with the Ubuntu 26.04 runner from #155.

The generated website is unchanged, and the integration and Playwright tests pass as before.

Builds on top of #147, #125, #155, #84, #115 and #68
Refs https://github.com/clue-engineering/miley/pull/86 (private)

[Copilot]

🟢 Approval recommended

The container build and workflow changes are consistent, with no unresolved findings.

No open issues 🎉

What changed in this PR

Moves website generation into Docker, reusing the container build for deployment without requiring local PHP or Composer.

Changes:

• Exports the generated site into build/ through Docker.
• Removes explicit PHP setup from CI and HTML-diff workflows.
• Documents container-based development requirements.

File	Description
README.md	Documents Docker-based development setup.
Makefile	Builds and exports the website through Docker.
Dockerfile	Separates site generation, export, and serving stages.
.github/​workflows/​diff.yml	Removes explicit PHP setup for HTML comparisons.
.github/​workflows/​ci.yml	Removes PHP setup from the deployment workflow.

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