Whitelist approach: ignore everything, then allow only what Docker builds need

This reduces build context from ~900MB to just what's required

Ignore everything first

=== n8n main image (docker/images/n8n/Dockerfile) ===

!compiled !compiled/** !THIRD_PARTY_LICENSES.md

=== runners image (docker/images/runners/Dockerfile + Dockerfile.distroless) ===

!dist !dist/task-runner-javascript !dist/task-runner-javascript/** !packages !packages/@n8n !packages/@n8n/task-runner-python !packages/@n8n/task-runner-python/**

=== Docker build files (entrypoints, configs) ===

!docker !docker/images !docker/images/n8n !docker/images/n8n/docker-entrypoint.sh !docker/images/runners !docker/images/runners/n8n-task-runners.json

=== benchmark image (packages/@n8n/benchmark/Dockerfile) ===

!package.json !pnpm-lock.yaml !pnpm-workspace.yaml !patches !patches/** !scripts !scripts/** !packages/@n8n/benchmark !packages/@n8n/benchmark/** !packages/@n8n/typescript-config !packages/@n8n/typescript-config/**