refactor(infra) : reorganize docker config into infra/dev and infra/prod

Align project structure with Lesstime: move docker/ to infra/dev/ and
deploy/ to infra/prod/. Update all references in docker-compose,
makefile, CI workflow, Dockerfile, .gitignore and .dockerignore.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -20,7 +20,7 @@
 ###< phpunit/phpunit ###
 
 ###> docker ###
-docker/.env.docker.local
+infra/dev/.env.docker.local
 ###< docker ###
 ###> migration archives ###
 /_archives/