feat(gate.yml): wire check-archive-header-section33.sh as enforcing CI lint (B-0036 Sub-task 2)

.github/workflows/gate.yml

@@ -325,8 +325,8 @@ jobs:
     # timestamp). This catches the recurring row-ordering bug
     # where the Edit tool's old_string=existing-line pattern
     # inserts the new row BEFORE the matched line, producing
-    # reverse-chronological order. Aaron 2026-04-26 asked for
-    # structural prevention after I caught this bug at least
+    # reverse-chronological order. Maintainer 2026-04-26 asked for
+    # structural prevention after the bug was caught at least
     # three times across recent ticks. The check is the
     # "fail-fast at commit/push time" mechanism that doesn't
     # rely on each agent's vigilance — Otto-339 anywhere-means-
@@ -346,7 +346,7 @@ jobs:
 
   lint-no-conflict-markers:
     # Fail if any committed file contains git merge-conflict markers
-    # (`<<<<<<<`, `=======`, `>>>>>>>`). Aaron 2026-04-26 ask:
+    # (`<<<<<<<`, `=======`, `>>>>>>>`). Maintainer 2026-04-26 ask:
     # *"maybe we should hygene for <<<<<<< HEAD and >>>>>>> ======= things
     # like that in our files incase we ever accidently botch a merge,
     # happens to the best of us humans too."*
@@ -368,6 +368,34 @@ jobs:
       - name: Run check-no-conflict-markers
         run: tools/hygiene/check-no-conflict-markers.sh
 
+  lint-archive-header-section33:
+    # Fail if any courier-ferry / external-conversation import under
+    # docs/research/** is missing the GOVERNANCE.md §33 4-field archive
+    # boundary header in the first 20 lines, OR if its 'Operational
+    # status:' value is not enum-strict ('research-grade' or
+    # 'operational'). Factory observation 2026-04-26: §33 archive header
+    # was the most-common review finding across the 11-refinement
+    # courier-ferry lineage this session — every PR retrofitted post-
+    # review.
+    #
+    # Per Otto-346 (recurring pattern → substrate primitive) +
+    # Otto-341 (mechanism over vigilance), this lint catches the
+    # discipline at the structural layer: agents and humans cannot
+    # land courier-ferry imports without the §33 header anymore.
+    #
+    # B-0036 Sub-task 2 — wire the lint to gate.yml after Sub-task 1
+    # backfilled all pre-existing violations to 0.
+    name: lint (archive header §33)
+    timeout-minutes: 2
+    runs-on: ubuntu-22.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Run check-archive-header-section33
+        run: tools/hygiene/check-archive-header-section33.sh
+
   lint-no-empty-dirs:
     # Fail if a committed directory has no files — almost always a
     # forgotten artefact (an agent-created skill folder without a