feat(packaging): an MSIX target for Microsoft Store submission

Store certification of the NSIS "MSI/EXE" submission failed on three
checks (silent-install verification, Add/Remove Programs entry, bundleware
check) -- traced and reproduced live to one cause: SmartScreen blocks an
unsigned, internet-downloaded installer at the shell layer before
Microsoft's own unattended validation bot ever gets to run it. MSIX
sidesteps this class of failure entirely: submitted through the Store's
native pipeline, there is no browser-download-then-launch step for
SmartScreen to intercept, and Microsoft signs the package itself at
publish time -- free, and specific to this submission type (Trusted
Signing remains a paid service for the MSI/EXE path). Full plan and
findings: C:\Users\admin\devel\msix-installer.md (out of repo).

electron-builder.msix.yml carries the same bundle as Full (node runtime,
ffmpeg, both service scripts) -- an AppX/MSIX install never elevates, by
design, but that changes only *when* the two elevated operations can run,
not whether the daemon ships. No main.js changes were needed: the on-demand
elevation path for service-mode (winElevateServiceMode(), driven from the
Node page) already existed for a different reason and depends only on
service-mode.ps1 being present as an extraResource, true for any packaged
Windows target. identityName/publisher/publisherDisplayName are the real
values from Partner Center's app-identity reservation, not placeholders.

build-win-msix.ps1 points electron-builder at the system Windows 10 SDK
(auto-detected) instead of letting it download its own bundled copy --
that download's 7z extraction creates symlinks this target never uses and
fails without SeCreateSymbolicLinkPrivilege, reproduced on this machine.
build/appx/ carries the four tile images the AppX target requires
regardless of showNameOnTiles, generated once from the existing app icon
(see that directory's README) since the system-SDK redirect has no vendor
samples to fall back to. build/appx-extensions.xml declares
windows.startupTask by hand rather than via electron-builder's
addAutoLaunchExtension, which always targets the Electron shell -- this
points at the bundled node binary instead, matching what "starts at sign
in" already means for Full.

Verified live via a signed sideload install (self-signed test cert,
cleaned up after): the package installs and the app runs correctly. One
finding worth carrying forward -- the declared network capabilities
(internetClientServer, privateNetworkClientServer) do not create any
firewall exemption for this app, most likely because automatic
capability-based exemption is an AppContainer-sandbox property and this
app deliberately runs full-trust, outside any sandbox. Not a regression:
no install-time elevation was possible either way, so the cost is the same
one-time OS firewall prompt firewall.ps1's own header already documents as
its fallback today.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 199 insertions, 5 deletions

diff --git a/packages/meshbay-node/tests/test_packaging_win.py b/packages/meshbay-node/tests/test_packaging_win.py
index b223156..2cc8f12 100644
--- a/packages/meshbay-node/tests/test_packaging_win.py
+++ b/packages/meshbay-node/tests/test_packaging_win.py
@@ -31,6 +31,13 @@ LIGHT_YML = WIN / "electron-builder.light.yml"
 BUILD_WIN_LIGHT = WIN / "build-win-light.ps1"
 BUILD_WIN_COMMON = WIN / "build-win-common.ps1"
 
+# The "MSIX" target: same feature set as Full, packaged for Microsoft Store
+# submission instead of NSIS. See C:\Users\admin\devel\msix-installer.md for
+# the plan this implements.
+MSIX_YML = WIN / "electron-builder.msix.yml"
+BUILD_WIN_MSIX = WIN / "build-win-msix.ps1"
+MSIX_EXTENSIONS_XML = CLIENT / "build" / "appx-extensions.xml"
+
 # sync-ui.js copies this into CLIENT/ui/ verbatim -- read the source of
 # truth, same as every other cross-package check in this file already does
 # for meshbay-client's own src/.
@@ -746,10 +753,10 @@ def test_build_win_light_skips_the_node_runtime_step():
 def test_build_orchestrators_share_the_common_steps_not_a_copy():
     """
     Node check / npm ci / Electron bump / sync-ui must live in exactly one
-    place (build-win-common.ps1), dot-sourced by both -- a copy would let
-    the two drift the way the installer flow itself once did (the W3
-    one-shot dialog bug). Both orchestrators must call the shared
-    functions, neither may inline its own npm ci / Electron-bump logic.
+    place (build-win-common.ps1), dot-sourced by all three orchestrators --
+    a copy would let them drift the way the installer flow itself once did
+    (the W3 one-shot dialog bug). Every orchestrator must call the shared
+    functions, none may inline its own npm ci / Electron-bump logic.
     """
     assert BUILD_WIN_COMMON.exists(), f"{BUILD_WIN_COMMON} is missing"
     common = BUILD_WIN_COMMON.read_text(encoding="utf-8")
@@ -758,7 +765,9 @@ def test_build_orchestrators_share_the_common_steps_not_a_copy():
 
     full = (WIN / "build-win.ps1").read_text(encoding="utf-8")
     light = BUILD_WIN_LIGHT.read_text(encoding="utf-8")
-    for src, name in ((full, "build-win.ps1"), (light, "build-win-light.ps1")):
+    msix = BUILD_WIN_MSIX.read_text(encoding="utf-8")
+    for src, name in ((full, "build-win.ps1"), (light, "build-win-light.ps1"),
+                       (msix, "build-win-msix.ps1")):
         assert '. (Join-Path $WinDir "build-win-common.ps1")' in src, (
             f"{name} does not dot-source build-win-common.ps1")
         for fn in ("Assert-NodeVersion", "Invoke-NpmCi", "Invoke-ElectronBump", "Invoke-SyncUi"):
@@ -908,3 +917,188 @@ def test_create_group_page_falls_back_when_no_node_is_bundled():
     assert "platform.node.bundled()" in body
     assert "platform.node.available && bundled" in body
     assert "CreateGroupWizard" in body and "CreateGroupFormSimple" in body
+
+
+# ------------------------------------------------------------------------
+# The "MSIX" target: same feature set as Full, packaged for Microsoft Store
+# submission instead of NSIS. See C:\Users\admin\devel\msix-installer.md for
+# the plan. Unlike Light, this target keeps the node runtime and both
+# service scripts -- what changes is packaging format, not what ships.
+# Weak, text-reading evidence throughout, same reasoning as the rest of
+# this file: there is no electron-builder/appx runner here either.
+# ------------------------------------------------------------------------
+
+def test_msix_config_is_standalone_and_keeps_the_full_bundle():
+    """
+    Unlike Light, MSIX ships the same node-runtime/ffmpeg/service scripts as
+    Full -- an AppX install never elevating (msix-installer.md 4) is not a
+    reason to drop the daemon, only to change how its two elevated
+    operations get triggered (see the two tests below). --config still
+    means this file is read alone (app-builder-lib's getConfig), so it
+    cannot silently inherit Full's package.json build.nsis or any signing
+    config meant for NSIS.
+    """
+    assert MSIX_YML.exists(), f"{MSIX_YML} is missing"
+    yml = MSIX_YML.read_text(encoding="utf-8")
+
+    assert "appId: org.meshbay.client" in yml
+    assert "target: appx" in yml
+    assert "output: dist-msix" in yml
+
+    assert "node-runtime" in yml
+    assert "service.ps1" in yml
+    assert "service-mode.ps1" in yml
+    assert "firewall.ps1" in yml
+
+
+def test_msix_identity_matches_the_partner_center_reservation():
+    """
+    identityName/publisher/publisherDisplayName are assigned by Partner
+    Center's "App identity" page when the app name is reserved -- they
+    cannot be chosen freely, and a mismatch fails Store validation outright
+    rather than warning. Pins the exact reservation (done 2026-09-11) so a
+    future edit cannot silently drift back to electron-builder's own
+    unconfigured-build stand-in ("CN=ms", see windowsSignToolManager.js's
+    computePublisherName) without a test noticing.
+    publisherDisplayName is "MeshBay" as Partner Center assigned it, NOT
+    package.json's author company name ("MeshBay Team") -- AppXOptions.d.ts's
+    own default (company name from app metadata) would pick the wrong one if
+    this were ever left unset instead of explicit.
+    """
+    yml = MSIX_YML.read_text(encoding="utf-8")
+    assert "identityName: MeshBay.MeshBay" in yml
+    assert 'publisher: "CN=CE32BB0D-6B7C-4D3A-AA42-E259B778CAC9"' in yml
+    assert "publisherDisplayName: MeshBay" in yml
+    assert '"CN=ms"' not in yml, (
+        "must not have drifted back to electron-builder's own placeholder "
+        "publisher")
+
+
+def test_msix_declares_no_csc_on_purpose():
+    """
+    No certificateFile/certificateSubjectName/certificateSha1 anywhere in
+    this config -- per app-builder-lib's own windowsSignToolManager.js, an
+    AppX target built with no certificate configured is logged as "Windows
+    Store only build" and left unsigned; Microsoft signs it at publish time
+    (msix-installer.md 3). Configuring a cert here would be wasted work, not
+    extra safety, and would risk this target picking up whatever might one
+    day be configured for Full's NSIS signing if it were ever added to this
+    file instead of package.json's own build.win.
+    """
+    yml = MSIX_YML.read_text(encoding="utf-8")
+    for forbidden in ("certificateFile", "certificateSubjectName", "certificateSha1"):
+        assert forbidden not in yml
+
+
+def test_msix_declares_the_network_capabilities_firewall_ps1_would_add():
+    """
+    Matches firewall.ps1's own rules, which are `-Profile Any` (private AND
+    public network) -- msix-installer.md 8's #1 open item: whether Windows
+    actually auto-exempts a full-trust packaged app on the strength of
+    these declarations is unverified until sideloaded, but the declaration
+    itself must at least match what the elevated NSIS path grants today, or
+    an MSIX install would be silently narrower than Full/Light.
+    """
+    yml = MSIX_YML.read_text(encoding="utf-8")
+    caps_block = yml.split("capabilities:", 1)[1].split("customExtensionsPath", 1)[0]
+    assert "internetClientServer" in caps_block
+    assert "privateNetworkClientServer" in caps_block
+
+
+def test_msix_startup_task_targets_the_node_not_the_electron_shell():
+    """
+    addAutoLaunchExtension's built-in windows.startupTask (app-builder-lib's
+    AppxTarget.js) always targets the package's own main executable -- the
+    Electron shell -- which is not what "starts at sign in" means today
+    (main.js's WIN_STARTUP_VBS launches meshbay-node.exe directly, keeping
+    the daemon running whether or not the UI is ever opened). This config
+    must NOT use addAutoLaunchExtension for that reason, and must instead
+    supply its own extension via customExtensionsPath pointing at the node
+    binary's in-package path -- app\\resources\\node-runtime\\meshbay-node.exe,
+    derived from AppxTarget.js's own `"app\\\\" + appOutDir-relative path`
+    mapping (build() in that file), which is not the same prefix
+    process.resourcesPath resolves to at runtime and easy to get wrong.
+    """
+    yml = MSIX_YML.read_text(encoding="utf-8")
+    # The comment explaining *why* addAutoLaunchExtension is not used
+    # necessarily names it -- check the directive, not the prose (the same
+    # "parse directives, not text" mistake CLAUDE.md's engineering lessons
+    # already record for a differently-shaped bug).
+    lines = [ln.strip() for ln in yml.splitlines()]
+    assert not any(ln.startswith("addAutoLaunchExtension:") for ln in lines), (
+        "must not set addAutoLaunchExtension -- it always targets the "
+        "Electron shell, not the node binary (see this test's docstring)")
+    assert "customExtensionsPath: build/appx-extensions.xml" in yml
+
+    assert MSIX_EXTENSIONS_XML.exists(), f"{MSIX_EXTENSIONS_XML} is missing"
+    ext = MSIX_EXTENSIONS_XML.read_text(encoding="utf-8")
+    assert 'Category="windows.startupTask"' in ext
+    assert 'Executable="app\\resources\\node-runtime\\meshbay-node.exe"' in ext
+    assert 'EntryPoint="Windows.FullTrustApplication"' in ext
+
+
+def test_msix_ships_the_four_required_tile_images():
+    """
+    app-builder-lib's AppxTarget.js requires StoreLogo/Square44x44Logo/
+    Square150x150Logo/Wide310x150Logo regardless of showNameOnTiles, falling
+    back to its own vendor-bundled samples if build/appx/ does not supply
+    them. This repo points ELECTRON_BUILDER_WINDOWS_KITS_PATH at the system
+    Windows SDK instead of that vendor bundle (build-win-msix.ps1), which
+    has no samples to fall back to -- so a missing one here is a hard
+    makeappx failure, not a cosmetic gap. See build/appx/README.md for
+    where these came from.
+    """
+    appx_assets = CLIENT / "build" / "appx"
+    for name in ("StoreLogo.png", "Square44x44Logo.png",
+                 "Square150x150Logo.png", "Wide310x150Logo.png"):
+        assert (appx_assets / name).exists(), f"{name} is missing from {appx_assets}"
+
+
+def test_build_win_msix_keeps_the_node_runtime_step():
+    """The opposite of Light's equivalent test: MSIX is Full's feature set,
+    repackaged -- build-node-runtime.ps1 must still run."""
+    assert BUILD_WIN_MSIX.exists(), f"{BUILD_WIN_MSIX} is missing"
+    src = BUILD_WIN_MSIX.read_text(encoding="utf-8")
+    assert "build-node-runtime.ps1" in src
+    assert "electron-builder.msix.yml" in src
+    assert "--config" in src
+    assert "--win appx" in src
+
+
+def test_dist_win_msix_delegates_to_the_msix_orchestrator():
+    pkg = _pkg()
+    scripts = pkg["scripts"]
+    assert "dist:win:msix" in scripts
+    assert "build-win-msix.ps1" in scripts["dist:win:msix"]
+
+
+def test_build_win_msix_points_electron_builder_at_the_system_sdk():
+    """
+    electron-builder's own bundled AppX tooling download (winCodeSign-*.7z)
+    extracts symlinks for binaries this target never uses and fails without
+    SeCreateSymbolicLinkPrivilege -- reproduced on this machine's build
+    shell. ELECTRON_BUILDER_WINDOWS_KITS_PATH (app-builder-lib's
+    getWindowsKitsBundle) is the documented escape hatch; this must be set
+    automatically, not left as a step a future build is expected to
+    remember.
+    """
+    src = BUILD_WIN_MSIX.read_text(encoding="utf-8")
+    assert "ELECTRON_BUILDER_WINDOWS_KITS_PATH" in src
+    assert "makeappx.exe" in src
+
+
+# ── main.js needs nothing new for this target ──────────────────────────────
+#
+# Unlike Light (which needed hasBundledNode/winCanElevateServiceMode/the
+# create-group gate because the bundle itself is smaller), MSIX ships
+# everything Full does, and the two elevation paths it cannot get from an
+# installer already exist independently of installer.nsh:
+# firewall.ps1's per-first-use Windows prompt (no admin needed for that
+# fallback -- see firewall.ps1's own header) and main.js's
+# winElevateServiceMode(), driven from the Node page ("the other door",
+# already exercised by test_can_elevate_checks_service_mode_ps1_actually_
+# exists above) rather than from setup. There is deliberately no
+# MSIX-specific test here pinning main.js: the Light-target tests above
+# already pin that winCanElevateServiceMode() checks for service-mode.ps1's
+# presence generically, which is exactly what makes it work for a third
+# packaged target without being told about it.