Update Dockerfile + dockerignore for monorepo build context

Build context for docs/Dockerfile is now the monorepo root, so the
gem/ subtree is visible to bundle install and `path: "../gem"` in
docs/Gemfile resolves correctly.

Run from the repo root:
  docker build -f docs/Dockerfile .
  flyctl deploy --config docs/fly.toml --dockerfile docs/Dockerfile .

Changes:
- COPY gem /gem before `bundle install`, then COPY docs/Gemfile and
  docs/Gemfile.lock into /rails/.
- COPY docs/package.json + docs/pnpm-lock.yaml separately, then COPY
  docs/ into /rails/ for the rest of the app code.
- Final stage copies /gem too so the running container resolves the
  gem path at boot.
- Move .dockerignore to repo root with paths rewritten to /docs/...
  and /gem/...; drop docs/.dockerignore.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cirdes

.dockerignore

@@ -0,0 +1,60 @@
+# Build context for docs/Dockerfile is the monorepo root.
+# See https://docs.docker.com/engine/reference/builder/#dockerignore-file
+
+# Ignore git directory.
+/.git/
+/.gitignore
+
+# Ignore bundler config in either subproject.
+/gem/.bundle
+/docs/.bundle
+
+# Ignore environment files.
+/docs/.env*
+/gem/.env*
+
+# Ignore default key files.
+/docs/config/master.key
+/docs/config/credentials/*.key
+
+# Ignore logs and tempfiles.
+/docs/log/*
+/docs/tmp/*
+!/docs/log/.keep
+!/docs/tmp/.keep
+/docs/tmp/pids/*
+!/docs/tmp/pids/.keep
+
+# Ignore storage (uploaded files in dev and SQLite databases).
+/docs/storage/*
+!/docs/storage/.keep
+/docs/tmp/storage/*
+!/docs/tmp/storage/.keep
+
+# Ignore assets.
+/docs/node_modules/
+/docs/app/assets/builds/*
+!/docs/app/assets/builds/.keep
+/docs/public/assets
+
+# Ignore gem build artifacts.
+/gem/pkg/
+/gem/node_modules/
+/gem/tmp/
+/gem/.ruby-lsp/
+
+# Ignore CI service files.
+/.github
+
+# Ignore Kamal files.
+/docs/config/deploy*.yml
+/docs/.kamal
+
+# Ignore development files.
+/gem/.devcontainer
+/docs/.devcontainer
+
+# Ignore Docker-related files.
+/.dockerignore
+/docs/.dockerignore
+/docs/Dockerfile*

docs/.dockerignore

@@ -1,7 +1,12 @@
 # syntax=docker/dockerfile:1
 # check=error=true
 
-# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
+# Build context for this Dockerfile is the monorepo root, not docs/.
+# Run from the repo root:
+#   docker build -f docs/Dockerfile .
+#   flyctl deploy --config docs/fly.toml --dockerfile docs/Dockerfile .
+
+# Make sure RUBY_VERSION matches the Ruby version in docs/.ruby-version
 ARG RUBY_VERSION=3.4.7
 FROM quay.io/evl.ms/fullstaq-ruby:${RUBY_VERSION}-jemalloc-slim AS base
 
@@ -43,18 +48,21 @@ RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz
     npm install -g pnpm@$PNPM_VERSION && \
     rm -rf /tmp/node-build-master
 
-# Install application gems
-COPY Gemfile Gemfile.lock ./
+# Copy the gem first so docs/Gemfile's `path: "../gem"` resolves during bundle install.
+COPY gem /gem
+
+# Install application gems (cwd = /rails)
+COPY docs/Gemfile docs/Gemfile.lock ./
 RUN bundle install && \
     rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
     bundle exec bootsnap precompile --gemfile
 
 # Install node modules
-COPY package.json ./
+COPY docs/package.json docs/pnpm-lock.yaml ./
 RUN pnpm install
 
 # Copy application code
-COPY . .
+COPY docs/ ./
 
 # Precompile bootsnap code for faster boot times
 RUN bundle exec bootsnap precompile app/ lib/
@@ -67,8 +75,9 @@ RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
 FROM base
 
 
-# Copy built artifacts: gems, application
+# Copy built artifacts: gems, application, and the gem subtree
 COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
+COPY --from=build /gem /gem
 COPY --from=build /rails /rails
 
 # Run and own only the runtime files as a non-root user for security