feat(linux): ship raw x86 AppImage, Flatpak bundle, and dual-env curl

Drop the pointless zip wrapper around the x86_64 AppImage, harden HostShell
so bundled curl keeps APPDIR libs while host curl scrubs LD_LIBRARY_PATH /
Steam LD_PRELOAD, and add a Flatpak channel with --device=all, bundled
curl, and AppStream releases metadata. Portable mode now probes writability
with a unique temp file and falls back soft on RO mounts / Flatpak.

scripts/build_flatpak.sh

@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+# Build a single-file Flatpak bundle for x86_64 desktop Linux.
+#
+# Usage: scripts/build_flatpak.sh [--version X.Y.Z] [--game-love PATH]
+#
+# Output:
+#   dist/flatpak/gen1recomp-<version>-linux.flatpak
+#
+# Requires: flatpak, flatpak-builder, and network on first run (Freedesktop
+# runtime + LÖVE AppImage download).
+
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+APP_ID="com.theboisclub.gen1recomp"
+VERSION="0.0.0"
+GAME_LOVE_IN=""
+DIST="$ROOT/dist/flatpak"
+BUILD_DIR="$ROOT/.bazinga/flatpak-build"
+REPO_DIR="$ROOT/.bazinga/flatpak-repo"
+STATE_DIR="$ROOT/.bazinga/flatpak-state"
+CACHE="$ROOT/.bazinga/flatpak-cache"
+
+say()  { printf '\033[1;32m==>\033[0m %s\n' "$*"; }
+warn() { printf '\033[1;33mwarn:\033[0m %s\n' "$*" >&2; }
+fail() { printf '\033[1;31merror:\033[0m %s\n' "$*" >&2; exit 1; }
+
+while [ $# -gt 0 ]; do
+  case "$1" in
+    --version) VERSION="$2"; shift ;;
+    --game-love) GAME_LOVE_IN="$2"; shift ;;
+    -h|--help)
+      sed -n '2,12p' "$0"
+      exit 0
+      ;;
+    *) fail "unknown argument: $1" ;;
+  esac
+  shift
+done
+
+if ! printf '%s' "$VERSION" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+$'; then
+  fail "invalid --version '$VERSION' (expected X.Y.Z)"
+fi
+
+command -v flatpak >/dev/null || fail "flatpak not found"
+command -v flatpak-builder >/dev/null || fail "flatpak-builder not found"
+
+mkdir -p "$DIST" "$BUILD_DIR" "$REPO_DIR" "$STATE_DIR" "$CACHE"
+
+LOVE_FILE="$CACHE/game.love"
+if [ -n "$GAME_LOVE_IN" ]; then
+  [ -f "$GAME_LOVE_IN" ] || fail "game.love not found: $GAME_LOVE_IN"
+  if [ "$(readlink -f "$GAME_LOVE_IN")" != "$(readlink -f "$LOVE_FILE")" ]; then
+    cp "$GAME_LOVE_IN" "$LOVE_FILE"
+  fi
+else
+  say "packing game.love"
+  "$ROOT/scripts/pack_love.sh" --output "$LOVE_FILE" --version "$VERSION"
+fi
+
+# Stage local sources next to the generated manifest (flatpak path: is relative).
+cp "$ROOT/flatpak/$APP_ID.desktop" "$CACHE/$APP_ID.desktop"
+# AppStream rejects icons larger than the declared hicolor size.
+if command -v magick >/dev/null 2>&1; then
+  magick "$ROOT/assets/logo/gen1recomp_cover.png" -resize 512x512 "$CACHE/icon.png"
+elif command -v convert >/dev/null 2>&1; then
+  convert "$ROOT/assets/logo/gen1recomp_cover.png" -resize 512x512 "$CACHE/icon.png"
+else
+  fail "need ImageMagick (magick/convert) to resize the Flatpak icon to 512x512"
+fi
+
+
+DATE="$(date -u +%Y-%m-%d)"
+python3 - "$ROOT/flatpak/$APP_ID.metainfo.xml" "$CACHE/$APP_ID.metainfo.xml" "$VERSION" "$DATE" <<'PY'
+import sys, pathlib, re
+src, dst, ver, date = sys.argv[1:5]
+text = pathlib.Path(src).read_text(encoding="utf-8")
+release = f'    <release version="{ver}" date="{date}"/>'
+text = re.sub(
+    r"<releases>.*?</releases>",
+    "<releases>\n" + release + "\n  </releases>",
+    text,
+    count=1,
+    flags=re.S,
+)
+pathlib.Path(dst).write_text(text, encoding="utf-8")
+PY
+
+cp "$ROOT/flatpak/$APP_ID.yml" "$CACHE/$APP_ID.yml"
+
+say "installing Freedesktop runtime (no-op if present)"
+flatpak --user remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo || true
+flatpak --user install -y flathub \
+  org.freedesktop.Platform//24.08 \
+  org.freedesktop.Sdk//24.08 \
+  || warn "runtime install reported an error; flatpak-builder may still reuse cache"
+
+say "building Flatpak ($APP_ID $VERSION)"
+# Run from CACHE so path: sources resolve.
+(
+  cd "$CACHE"
+  flatpak-builder --user --force-clean \
+    --state-dir="$STATE_DIR" \
+    --repo="$REPO_DIR" \
+    "$BUILD_DIR" "$APP_ID.yml"
+)
+
+OUT="$DIST/gen1recomp-${VERSION}-linux.flatpak"
+rm -f "$OUT"
+say "exporting bundle $OUT"
+flatpak build-bundle "$REPO_DIR" "$OUT" "$APP_ID" \
+  --runtime-repo=https://flathub.org/repo/flathub.flatpakrepo
+chmod 644 "$OUT"
+if command -v sha256sum >/dev/null 2>&1; then
+  printf '%s  %s\n' "$(sha256sum "$OUT" | awk '{print $1}')" "$(basename "$OUT")" > "$OUT.sha256"
+else
+  printf '%s  %s\n' "$(shasum -a 256 "$OUT" | awk '{print $1}')" "$(basename "$OUT")" > "$OUT.sha256"
+fi
+say "Flatpak build: $OUT ($(du -h "$OUT" | cut -f1))"
+say "sha256: $(cut -d' ' -f1 "$OUT.sha256")"