ci: add HUD installer regression gate to canary + e2e workflows (#1490)

Adds the v5.6.2 regression gate to two CI workflows so a broken
installer cannot reach canary or release:

1. canary.yml — new ``plugin-hooks-tests`` job (Python pytest only,
   no node/yarn build needed) blocks ``publish-canary`` via ``needs``.
   Triggered on master/stag-** push, so master merges are gated
   before any canary npm publish.

2. e2e-plugin.yml — adds the same pytest invocation + simulation
   script step to the existing ``e2e-plugin-hooks`` job, and extends
   ``paths`` to include ``packages/claude-code-plugin/tests/**`` and
   ``scripts/verify-install-simulation.sh`` so PR-level changes
   trigger the gate. e2e-plugin runs on non-master branches, so
   PRs see the gate before merge.

Together the two jobs cover both PR review (e2e-plugin) and
post-merge canary publish (canary), so the v5.6.0/v5.6.1 failure
mode (installer ships without lib sync, all users see the fallback
face) cannot recur silently.

Test invocations cover all five v5.6.2 hotfix test files:
  - tests/test_atomic_sync_with_lib.py    (9 tests)
  - tests/test_session_start_hud.py       (20 tests)
  - tests/test_install_hook_with_lib.py   (4 tests)
  - tests/test_health_check.py            (35 tests)
  - scripts/verify-install-simulation.sh  (subprocess render gate)

actions/setup-python pin reused from existing e2e-plugin.yml entry
(SHA a26af69be951a213d495a4c3e4e4022e16d87065 = v5.6.0).

Refs #1490

Author: JeremyDev87

.github/workflows/canary.yml

@@ -21,7 +21,41 @@ permissions:
   contents: read
 
 jobs:
+  plugin-hooks-tests:
+    # Regression gate for #1490 — HUD installer must sync hooks/lib
+    # alongside the script. This job runs the Python pytest suites for
+    # the plugin hooks (no node/yarn build needed) so a broken installer
+    # cannot ship to canary or release.
+    if: github.repository == 'JeremyDev87/codingbuddy'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Setup Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: '3.11'
+
+      - name: Install pytest
+        run: python3 -m pip install --quiet pytest
+
+      - name: Run plugin hook test suites (#1490 regression gate)
+        working-directory: packages/claude-code-plugin
+        run: |
+          python3 -m pytest \
+            tests/test_atomic_sync_with_lib.py \
+            tests/test_session_start_hud.py \
+            tests/test_install_hook_with_lib.py \
+            tests/test_health_check.py \
+            -v --tb=short
+
+      - name: HUD install simulation (#1490 end-to-end gate)
+        run: bash packages/claude-code-plugin/scripts/verify-install-simulation.sh
+
   publish-canary:
+    needs: plugin-hooks-tests
     if: github.repository == 'JeremyDev87/codingbuddy'
     runs-on: ubuntu-latest
     timeout-minutes: 20

.github/workflows/e2e-plugin.yml

@@ -7,6 +7,8 @@ on:
       - stag-**
     paths:
       - 'packages/claude-code-plugin/hooks/**'
+      - 'packages/claude-code-plugin/tests/**'
+      - 'packages/claude-code-plugin/scripts/verify-install-simulation.sh'
       - 'tests/e2e/plugin-hooks/**'
       - .github/workflows/e2e-plugin.yml
 
@@ -50,6 +52,19 @@ jobs:
       - name: Run E2E plugin hook tests
         run: python3 -m pytest tests/e2e/plugin-hooks/ -v --timeout=30 --tb=short
 
+      - name: Plugin hook unit/E2E regression suites (#1490)
+        working-directory: packages/claude-code-plugin
+        run: |
+          python3 -m pytest \
+            tests/test_atomic_sync_with_lib.py \
+            tests/test_session_start_hud.py \
+            tests/test_install_hook_with_lib.py \
+            tests/test_health_check.py \
+            -v --tb=short
+
+      - name: HUD install simulation (#1490 end-to-end gate)
+        run: bash packages/claude-code-plugin/scripts/verify-install-simulation.sh
+
   e2e-plugin-docker:
     if: github.repository == 'JeremyDev87/codingbuddy'
     runs-on: ubuntu-latest