ci: temporarily disable serial reference runners

.github/workflows/ci.yml

@@ -27,6 +27,9 @@ env:
 
 jobs:
 
+  # TEMPORARY: the four serial reference jobs remain defined but cannot run.
+  # Restore their master-push conditions to re-enable them.
+
   # Three enterprise jobs isolate coverage, static analysis, and the
   # build-backed consumer tail. The static job publishes its exact build so
   # consumers do not repeat the longest part of their critical path.
@@ -39,8 +42,8 @@ jobs:
   # three onto the in-house
   # vm-backup pool and re-running the failed jobs is the entire switch —
   # see .agents/notes/implemented/process/2026-07-26-ci-failover-runbook.md. The
-  # in-house pool's readiness is re-proven on every master push by the
-  # serial-linux-selfhosted standby lane below.
+  # Normally, the in-house pool's readiness is re-proven on every master push
+  # by the serial-linux-selfhosted standby lane below.
   node-24:
     if: github.event_name == 'pull_request'
     runs-on: >-
@@ -225,8 +228,8 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-node-${{ env.PRIMARY_NODE_VERSION }}-pnpm-
 
-      # Pull requests restore the cache produced by serial-linux on master;
-      # they do not pay compression and upload on the required path.
+      # Pull requests restore the cache normally produced by serial-linux on
+      # master; they do not pay compression and upload on the required path.
       - uses: actions/cache/restore@v4
         if: vars.DSH_CI_FAILOVER != 'selfhosted' || github.event.pull_request.user.login == 'dependabot[bot]'
         with:
@@ -321,8 +324,9 @@ jobs:
   # The required pull-request Windows signal: the two blocking win32 surfaces
   # (workspace build, production site) execute with real, checksum-verified
   # Windows Node under Wine on standard hosted Linux. The master
-  # serial-windows job below keeps the complete native-kernel inventory —
-  # including the observational portability gates this lane does not run —
+  # serial-windows job below normally keeps the complete native-kernel
+  # inventory — including the observational portability gates this lane does
+  # not run —
   # on real windows-2025. This job only provisions runner state (caches,
   # apt); scripts/wine-windows-gates.sh owns the gate logic and is the same
   # script the optional local gate `pnpm run check:windows-wine` runs.
@@ -427,12 +431,12 @@ jobs:
           cp /var/cache/apt/archives/*.deb "$HOME/wine-debs/"
           du -sh "$HOME/wine-debs"
 
-  # Master pushes run only the serial reference jobs below.
-  # Each host executes the complete, unsharded primary Node aggregate with one
-  # gate worker, giving reviewers a simple cross-platform oracle for completeness
-  # and timing.
+  # The disabled definitions below normally run on master pushes. When
+  # enabled, each host executes the complete, unsharded primary Node aggregate
+  # with one gate worker, giving reviewers a simple cross-platform oracle for
+  # completeness and timing.
   serial-linux:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    if: false
     name: serial / linux
     runs-on: ubuntu-latest
     steps:
@@ -511,7 +515,7 @@ jobs:
   # tool caches make them redundant (and saving here would poison the hosted
   # cache namespace with self-hosted paths).
   serial-linux-selfhosted:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    if: false
     name: serial / linux (self-hosted standby)
     runs-on: [self-hosted, linux, x64, vm-backup]
     steps:
@@ -557,7 +561,7 @@ jobs:
         run: pnpm run check:ci:linux-primary
 
   serial-macos:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    if: false
     name: serial / macos
     runs-on: macos-latest
     steps:
@@ -584,7 +588,7 @@ jobs:
         run: pnpm run check:ci
 
   serial-windows:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    if: false
     name: serial / windows
     runs-on: windows-2025
     steps: