Add local Docker deployment and submodules

- docker-compose.yml: builder, nginx web server and a LaTeX container (profile "latex")
  for regenerating the SVG drawings
- Makefile, scripts/fetch.sh, .env.example
- 50ohm, 50ohm-contents-dl and 50ohm-ansible as submodules tracking branch sv

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

scripts/fetch.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Fetch (or update) the three repos this deployment is built from.
+#
+#   scripts/fetch.sh            clone/init the submodules, check out and fast-forward branch "sv" in each
+#   scripts/fetch.sh --pinned   check out exactly the commits recorded in this repo (detached HEAD)
+#
+# Also adds the original DARC repos as the local-only remote "upstream", so upstream changes
+# can be pulled in with `git fetch upstream`.
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+BRANCH=sv
+declare -A UPSTREAM=(
+  [50ohm]=https://github.com/DARC-e-V/50ohm.git
+  [50ohm-contents-dl]=https://github.com/DARC-e-V/50ohm-contents-dl.git
+  [50ohm-ansible]=https://github.com/DARC-e-V/50ohm-ansible.git
+)
+
+git submodule sync --quiet
+git submodule update --init
+
+for repo in "${!UPSTREAM[@]}"; do
+  if ! git -C "$repo" remote | grep -qx upstream; then
+    git -C "$repo" remote add upstream "${UPSTREAM[$repo]}"
+    echo "$repo: added remote upstream"
+  fi
+  if [[ "${1:-}" != "--pinned" ]]; then
+    git -C "$repo" fetch --quiet origin
+    git -C "$repo" checkout --quiet "$BRANCH"
+    git -C "$repo" merge --quiet --ff-only "origin/$BRANCH" || echo "$repo: $BRANCH has local commits, not fast-forwarded"
+  fi
+  echo "$repo: $(git -C "$repo" rev-parse --abbrev-ref HEAD) @ $(git -C "$repo" rev-parse --short HEAD)"
+done
+
+[[ -f .env ]] || { cp .env.example .env && echo "created .env from .env.example"; }
+echo "Done. Next: make build && make up"