feat(m6c): add Linux release package and delivery docs

[Change Nature]
- This commit adds the M6c Linux delivery surface without changing simulation behavior.

[New Capability]
- Publish self-contained linux-x64 output with framework-dependent fallback and a package-relative launcher.
- Document the menu, controls, save paths, autoplay verification, milestones, and asset/license boundaries.

[Implementation]
- Add the M6c packaging and startup scripts.
- Add release notes and an asset/license inventory.
- Keep release artifacts and verification evidence under ignored artifacts/m6c-release/.

[Impact]
- Runtime code and M3 acceptance artifacts are unchanged.
- The package was exercised under Xvfb; prior provider metadata remains an unstaged worktree change.

1 files changed, 75 insertions, 0 deletions

diff --git a/scripts/m6c-package.sh b/scripts/m6c-package.sh
new file mode 100755
index 0000000..d887ea6
--- /dev/null
+++ b/scripts/m6c-package.sh
@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(CDPATH= cd -- "$SCRIPT_DIR/.." && pwd)"
+PROJECT="$REPO_ROOT/src/LivingVillage.Desktop/LivingVillage.Desktop.fsproj"
+STAMP="${M6C_TIMESTAMP:-$(date -u +%Y%m%dT%H%M%SZ)}"
+PACKAGE_ROOT="$REPO_ROOT/artifacts/m6c-release/$STAMP"
+APP_DIR="$PACKAGE_ROOT/app"
+PUBLISH_LOG="$PACKAGE_ROOT/publish.log"
+
+if [[ -e "$PACKAGE_ROOT" ]]; then
+    printf 'Refusing to overwrite existing package directory: %s\n' "$PACKAGE_ROOT" >&2
+    exit 2
+fi
+
+if ! command -v dotnet >/dev/null 2>&1; then
+    printf 'dotnet SDK is required to build the Linux package.\n' >&2
+    exit 127
+fi
+
+mkdir -p "$APP_DIR"
+
+publish_args=(
+    "$PROJECT"
+    --configuration Release
+    --runtime linux-x64
+    --output "$APP_DIR"
+    --nologo
+    -p:DebugType=None
+    -p:DebugSymbols=false
+)
+
+runtime_mode="self-contained"
+self_contained_exit=0
+if dotnet publish "${publish_args[@]}" --self-contained true >"$PUBLISH_LOG" 2>&1; then
+    :
+else
+    self_contained_exit=$?
+    runtime_mode="framework-dependent"
+    rm -rf "$APP_DIR"
+    mkdir -p "$APP_DIR"
+    if ! dotnet publish "${publish_args[@]}" --self-contained false >>"$PUBLISH_LOG" 2>&1; then
+        printf 'Both self-contained and framework-dependent publish failed. See %s\n' "$PUBLISH_LOG" >&2
+        exit 1
+    fi
+fi
+
+cp "$SCRIPT_DIR/m6c-run.sh" "$PACKAGE_ROOT/run-living-village.sh"
+chmod +x "$PACKAGE_ROOT/run-living-village.sh"
+cp "$REPO_ROOT/README.md" "$PACKAGE_ROOT/README.md"
+cp "$REPO_ROOT/docs/release-notes-m6c.md" "$PACKAGE_ROOT/RELEASE-NOTES-M6C.md"
+cp "$REPO_ROOT/docs/assets-and-licenses.md" "$PACKAGE_ROOT/ASSETS-AND-LICENSES.md"
+
+source_commit="unknown"
+if git -C "$REPO_ROOT" rev-parse HEAD >/dev/null 2>&1; then
+    source_commit="$(git -C "$REPO_ROOT" rev-parse HEAD)"
+fi
+
+{
+    printf 'package=M6c Linux x64\n'
+    printf 'created_utc=%s\n' "$STAMP"
+    printf 'source_commit=%s\n' "$source_commit"
+    printf 'runtime_mode=%s\n' "$runtime_mode"
+    printf 'rid=linux-x64\n'
+    printf 'entrypoint=run-living-village.sh\n'
+    printf 'native_desktopgl_dependencies=system-provided\n'
+    if [[ "$runtime_mode" == "framework-dependent" ]]; then
+        printf 'self_contained_publish_exit=%s\n' "$self_contained_exit"
+        printf 'framework_dependent_requirement=.NET 8 runtime\n'
+    fi
+} > "$PACKAGE_ROOT/PACKAGE-INFO.txt"
+
+printf 'M6C_PACKAGE_DIR=%s\n' "$PACKAGE_ROOT"
+printf 'M6C_RUNTIME_MODE=%s\n' "$runtime_mode"