refactor(landlock-run): unify workspace release (review round 1)

.github/workflows/sandbox.yml

@@ -3,9 +3,8 @@
 # .agents/notes/implemented/process/2026-07-21-serial-cross-platform-ci-reference.md.
 # A separate workflow from ci.yml because the axis is different — these jobs
 # fan out over OS×runner (kernel capabilities), not node versions. The Landlock
-# launcher arrives from the registry with `pnpm install` (the npm package family
-# `node-addon-landlock-run`, built and released from its own repository), so
-# these legs exercise the true consumer path — nothing is compiled here.
+# launcher is built from native/landlock-run on each Landlock leg and installed
+# from the same tarballs the main-repository release workflow publishes.
 name: Sandbox
 
 on:
@@ -30,7 +29,7 @@ jobs:
   # an OS×runner matrix — bwrap and Landlock on Linux (separate legs: the
   # Landlock files force the bwrap rung off, so each leg proves exactly one
   # rung; Landlock twice, once per architecture, each confining through the
-  # registry-installed launcher), Seatbelt on macOS (sandbox-exec ships with
+  # locally built launcher), Seatbelt on macOS (sandbox-exec ships with
   # the OS). One node
   # version only: kernel confinement does not vary by node, and ci.yml's
   # node matrix already covers the node axis.
@@ -80,6 +79,14 @@ jobs:
           sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 \
             || echo "apparmor userns knob absent — the functional probe decides"
 
+      - name: Build Landlock launcher for this architecture
+        if: matrix.runner == 'landlock'
+        run: |
+          sudo apt-get update -q
+          sudo apt-get install -yq musl-tools
+          pnpm --dir native/landlock-run run build:ts
+          pnpm --dir native/landlock-run run build:native
+
       # The unit suite runs on ubuntu in `checks`; this is the one darwin leg
       # in the workflow, so run it here too — the platform-dependent unit
       # expectations (Seatbelt path canonicalization: /tmp IS /private/tmp)
@@ -105,14 +112,10 @@ jobs:
           # the very platform that exists to prove it) is a failure, not a pass.
           echo "$out" | grep -qE 'Test Files[[:space:]]+2 passed \(2\)'
 
-      # Publish-path rehearsal, Landlock legs only (the pack gates need built
-      # lib/). The e2e packs the workspace closure, installs the tarballs
-      # into a throwaway consumer — npm pulling `node-addon-landlock-run`
-      # and its platform package from the registry, the true consumer path —
-      # and confines through the INSTALLED launcher, asserting it executable
-      # apart (a mode-stripped binary must not masquerade as a non-enforcing
-      # kernel). Same no-silent-skip guard as above.
-      - name: Build packages (lib/ for the pack rehearsal)
+      # Publish-path rehearsal, Landlock legs only. Build the launcher on its
+      # native architecture, then install the local native and harness tarballs
+      # together so registry state cannot mask source/package drift.
+      - name: Build packages for the pack rehearsal
         if: matrix.runner == 'landlock'
         run: pnpm run build