fix(changelog): break infinite regenerate self-trigger loop

.github/workflows/changelog-reusable.yml

@@ -29,6 +29,19 @@
 #   `check-only`    - Render the changelog but do NOT commit. Fail the job if
 #                     the on-disk CHANGELOG.md disagrees with the regenerated
 #                     output. Use as a `pull_request` gate.
+#
+# Loop-prevention (surfaced by maa-framework PR #219): two complementary guards
+# prevent the workflow from reacting to its own output and opening an infinite
+# chain of changelog PRs:
+#   1. The canonical cliff.toml has a `skip = true` parser for the bot's own
+#      "chore(changelog): regenerate from conventional commits" subjects. This
+#      is the primary fix because it survives GitHub squash-merge (which uses
+#      the PR title as the new subject).
+#   2. Every commit/PR this workflow produces carries a [skip changelog]
+#      marker in its body, and the `guard` job below bails out entirely when
+#      the triggering HEAD commit already has that marker. This protects
+#      `commit-back` mode callers (where the auto commit lands directly on
+#      main without a squash step) and provides defense-in-depth for pr-back.
 
 on:
   workflow_call:
@@ -50,11 +63,46 @@
         default: '2.6.1'
 
 permissions:
   actions: read
   contents: read
 
 jobs:
+  guard:
+    name: Check for self-trigger loop
+    runs-on: ${{ inputs.runs-on }}
+    outputs:
+      skip: ${{ steps.loopguard.outputs.skip }}
+    steps:
+      - name: Checkout caller (HEAD only is enough for the guard)
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          repository: ${{ github.repository }}
+          ref: ${{ github.ref }}
+          fetch-depth: 1
+          path: caller
+
+      - name: Loop guard
+        id: loopguard
+        working-directory: caller
+        run: |
+          set -euo pipefail
+          # If the push that triggered us is itself a changelog regeneration
+          # (commit-back's direct commit, or a squash-merged pr-back PR whose
+          # body still contains the [skip changelog] marker placed below),
+          # skip the whole generate job. cliff.toml's subject-matcher is the
+          # primary fix; this guard handles cases where the marker is on the
+          # body (e.g. commit-back mode, rebase-merges, mergers who preserve
+          # the PR body).
+          if git log -1 --pretty=%B | grep -q '\[skip changelog\]'; then
+            echo "HEAD commit carries [skip changelog]; skipping generate job to break the regenerate loop."
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
   generate:
+    needs: guard
+    if: ${{ needs.guard.outputs.skip != 'true' }}
     timeout-minutes: 10
     name: Generate CHANGELOG.md
     runs-on: ${{ inputs.runs-on }}
@@ -151,6 +199,8 @@
           fi
           git commit -m "chore(changelog): regenerate from conventional commits
 
+          [skip changelog]
+
           Auto-generated by hyperpolymath/standards changelog-reusable.yml.
           See standards/templates/cliff.toml for the canonical config.
 
@@ -174,12 +224,35 @@
           git config user.name "github-actions[bot]"
           git checkout -b "$branch"
           git add CHANGELOG.md
-          git commit -m "chore(changelog): regenerate from conventional commits"
+          git commit -m "chore(changelog): regenerate from conventional commits
+
+          [skip changelog]"
           git push -u origin "$branch"
+          # Before opening a new PR, close any older open bot/changelog-* PRs
+          # against the same base so we don't accumulate duplicate PRs if a
+          # maintainer hasn't merged the previous one before another push lands.
+          for pr in $(gh pr list --repo "${{ github.repository }}" \
+                                 --base "${{ github.ref_name }}" \
+                                 --head 'bot/changelog-' \
+                                 --state open \
+                                 --json number,headRefName \
+                                 --jq '.[] | select(.headRefName != "'"$branch"'") | .number'); do
+            echo "Closing superseded changelog PR #$pr"
+            gh pr close "$pr" --repo "${{ github.repository }}" \
+              --comment "Superseded by a newer changelog regeneration PR."
+          done
           gh pr create \
+            --repo "${{ github.repository }}" \
             --title "chore(changelog): regenerate from conventional commits" \
             --body "Auto-generated by hyperpolymath/standards changelog-reusable.yml.
 
+            [skip changelog]
+
+            This PR body carries the [skip changelog] marker so that a
+            squash-merge of this PR will not re-trigger the changelog
+            workflow (loop-prevention added in response to maa-framework#219).
+            Please do not remove that marker when editing the description.
+
             Closes part of the 2026-05-26 CHANGELOG gap (standards#197 audit)." \
             --base "${{ github.ref_name }}" \
             --head "$branch"

templates/cliff.toml

@@ -54,6 +54,15 @@ commit_parsers = [
   { message = "^docs",     group = "Documentation" },
   { message = "^test",     group = "Tests" },
   { message = "^ci",       group = "CI" },
+  # Never re-emit the auto-changelog's own commits; that causes an infinite
+  # regenerate loop (surfaced by maa-framework PR #219). Must come BEFORE
+  # the generic ^chore matcher because commit_parsers is first-match-wins.
+  # The regex matches both the bot's branch commit subject and the default
+  # GitHub squash-merge subject ("... (#NNN)"), which is critical because
+  # in pr-back mode the squash-merge subject (not the branch commit body)
+  # survives into main.
+  { message = "^chore\\(changelog\\):\\s*regenerate from conventional commits", skip = true },
+  { body    = "\\[skip changelog\\]", skip = true },
   { message = "^chore",    group = "Chores" },
   { message = "^style",    skip   = true },
   { message = "^revert",   group = "Reverted" },