packaging: macOS app and dmg, Linux tar.gz and AppImage, Windows zip

packaging/macos/package.sh builds FieldCraft.app (io.github.jyviko.fieldcraft, with icon.icns
and the layered Assets.car), signs it with a Developer ID and notarizes it when the
credentials are there and ad-hoc otherwise, and puts it on a drag-to-Applications dmg that
is mounted and checked; fieldcraft-cli goes in its own zip. packaging/linux/package.sh makes
an FHS tar.gz (binaries, .desktop entry, hicolor icons, licences) and an AppImage made with
appimagetool and the type 2 runtime at pinned, hash-checked releases.
packaging/windows/package.ps1 zips fieldcraft.exe and fieldcraft-cli.exe (static CRT,
checked PE headers and icon). Every package carries README.md, LICENSE-MIT, LICENSE-APACHE,
NOTICE and THIRD-PARTY-LICENSES.txt (#72).

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

packaging/env.sh

@@ -0,0 +1,58 @@
+# shellcheck shell=bash
+# Shared setup for the packaging scripts. Source it: `. "$(dirname "$0")/../env.sh"`.
+# Adapted from SolidCraft's and VectorCraft's packaging (MIT OR Apache-2.0; see ATTRIBUTION.md).
+#
+# Exports:
+#   ROOT                    workspace root
+#   VERSION                 [workspace.package] version from Cargo.toml (override: FIELDCRAFT_VERSION)
+#   DIST                    output directory for release artifacts (default: $ROOT/dist/release)
+#   FIELDCRAFT_BUILD_SHA    the commit being packaged (recorded in the macOS Info.plist)
+#   CARGO_TARGET_DIR        cargo's target dir (default: $ROOT/target)
+#   APP_ID                  the reverse-DNS id: macOS bundle id, Linux .desktop and icon name, and
+#                           the window's Wayland app_id / X11 class (apps/fieldcraft/src/main.rs)
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+export ROOT
+
+# The version lives in one place: `[workspace.package] version` in the root Cargo.toml.
+workspace_version() {
+  awk '
+    /^\[/ { in_pkg = ($0 == "[workspace.package]") ; next }
+    in_pkg && $1 == "version" { gsub(/[" ]/, "", $3); print $3; exit }
+  ' "$ROOT/Cargo.toml"
+}
+
+VERSION="${FIELDCRAFT_VERSION:-$(workspace_version)}"
+if [ -z "$VERSION" ]; then
+  echo "error: could not read [workspace.package] version from $ROOT/Cargo.toml" >&2
+  exit 1
+fi
+export VERSION
+
+DIST="${DIST:-$ROOT/dist/release}"
+mkdir -p "$DIST"
+DIST="$(cd "$DIST" && pwd)"
+export DIST
+
+FIELDCRAFT_BUILD_SHA="${FIELDCRAFT_BUILD_SHA:-$(git -C "$ROOT" rev-parse HEAD 2>/dev/null || echo unknown)}"
+export FIELDCRAFT_BUILD_SHA
+export CARGO_TARGET_DIR="${CARGO_TARGET_DIR:-$ROOT/target}"
+APP_ID=io.github.jyviko.fieldcraft
+export APP_ID
+
+# Emit a GitHub Actions warning (plain stderr outside Actions).
+warn() {
+  if [ -n "${GITHUB_ACTIONS:-}" ]; then echo "::warning::$*"; else echo "warning: $*" >&2; fi
+}
+
+# The readme, licence, notice and third-party licence files every package carries
+# (packaging/windows/package.ps1 has the same list).
+DOC_FILES=(README.md LICENSE-MIT LICENSE-APACHE NOTICE THIRD-PARTY-LICENSES.txt)
+
+# Copy DOC_FILES into a package directory.
+copy_docs() {
+  local dest="$1" f
+  for f in "${DOC_FILES[@]}"; do
+    cp "$ROOT/$f" "$dest/"
+  done
+}