ci: add deterministic changelog-draft workflow

Drafts CHANGELOG_PENDING.md entries from Conventional Commit subjects on
every push to main -- feat/fix/refactor/perf/security bucketed into
Added/Fixed/Changed, chore/ci/test/docs/style/merge skipped, anything
mentioning internal infra hostnames dropped. No LLM call, no network
access. Never touches CHANGELOG.md -- still needs a human to fold an
entry in. Rolled out fleet-wide from the PeerCortex pilot (2026-07-18).

.github/scripts/changelog-draft.py

@@ -0,0 +1,105 @@
+#!/usr/bin/env python3
+"""Draft CHANGELOG_PENDING.md entries from Conventional Commit messages
+pushed since the last run. Deterministic -- no LLM call, no network access.
+Human review still required before folding an entry into CHANGELOG.md.
+"""
+import re
+import subprocess
+import sys
+from datetime import datetime, timezone
+
+INCLUDE_TYPES = {
+    "feat": "Added",
+    "fix": "Fixed",
+    "refactor": "Changed",
+    "perf": "Changed",
+    "security": "Fixed",
+}
+SKIP_TYPES = {"chore", "ci", "test", "docs", "style", "merge"}
+
+# Anything mentioning internal infra by name/address is dropped rather than
+# drafted -- better a missing entry (caught in human review) than a leaked one.
+INTERNAL_PATTERN = re.compile(
+    r"\b(erik|gitea\.context-x|192\.168\.|10\.10\.0\.|opnsense|ssh |systemd|pm2 |crontab)\b",
+    re.IGNORECASE,
+)
+
+PENDING_HEADER = (
+    "# Pending Changelog Entries\n\n"
+    "Drafted automatically from commit messages since the last processed "
+    "push. Review, edit as needed, and fold into CHANGELOG.md -- then clear "
+    "this file.\n\n"
+    "<!-- PENDING_ENTRIES -->\n"
+)
+
+
+def run(cmd):
+    return subprocess.check_output(cmd, shell=True, text=True).strip()
+
+
+def main():
+    before = sys.argv[1] if len(sys.argv) > 1 else ""
+    after = sys.argv[2] if len(sys.argv) > 2 else "HEAD"
+    if not before or set(before) == {"0"}:
+        print("No usable commit range (first push on branch) -- skipping.")
+        return
+
+    try:
+        log = run("git log {}..{} --format='%s'".format(before, after))
+    except subprocess.CalledProcessError:
+        print("Could not diff commit range -- skipping.")
+        return
+    if not log:
+        print("No new commits.")
+        return
+
+    buckets = {"Added": [], "Fixed": [], "Changed": []}
+    for subject in log.splitlines():
+        m = re.match(r"^(\w+)(\([\w./-]+\))?!?:\s*(.+)$", subject)
+        if not m:
+            continue
+        ctype, _, desc = m.groups()
+        ctype = ctype.lower()
+        if ctype in SKIP_TYPES or ctype not in INCLUDE_TYPES:
+            continue
+        if INTERNAL_PATTERN.search(desc):
+            continue
+        buckets[INCLUDE_TYPES[ctype]].append(desc.strip())
+
+    if not any(buckets.values()):
+        print("Nothing changelog-worthy in this push.")
+        return
+
+    date = datetime.now(timezone.utc).strftime("%Y-%m-%d")
+    lines = ["## Pending -- {}\n".format(date)]
+    for section in ("Added", "Fixed", "Changed"):
+        if buckets[section]:
+            lines.append("### {}".format(section))
+            for item in buckets[section]:
+                lines.append("- {}".format(item))
+            lines.append("")
+    entry = "\n".join(lines).rstrip() + "\n\n"
+
+    try:
+        with open("CHANGELOG_PENDING.md", "r") as f:
+            existing = f.read()
+        if not existing.strip():
+            existing = PENDING_HEADER  # pre-existing but empty placeholder file
+    except FileNotFoundError:
+        existing = PENDING_HEADER
+
+    marker = "<!-- PENDING_ENTRIES -->\n"
+    if marker in existing:
+        head, tail = existing.split(marker, 1)
+        updated = head + marker + entry + tail.lstrip("\n")
+    else:
+        updated = existing.rstrip("\n") + "\n\n" + entry
+
+    with open("CHANGELOG_PENDING.md", "w") as f:
+        f.write(updated)
+
+    print("Wrote entry:\n" + entry)
+
+
+if __name__ == "__main__":
+    main()

.github/workflows/changelog-draft.yml

@@ -0,0 +1,39 @@
+name: changelog-draft
+
+# Drafts CHANGELOG_PENDING.md entries from Conventional Commit subjects on
+# every push to main. Deterministic -- regex-parses commit subjects only,
+# no LLM call, no network access. Buckets feat/fix/refactor/perf/security
+# into Added/Fixed/Changed; skips chore/ci/test/docs/style/merge commits and
+# anything mentioning internal infra hostnames/addresses. Never touches
+# CHANGELOG.md itself -- human review still required to fold an entry in.
+
+on:
+  push:
+    branches: [main]
+
+permissions:
+  contents: write
+
+jobs:
+  changelog-draft:
+    runs-on: ubuntu-latest
+    if: "!contains(github.event.head_commit.message, '[skip ci]')"
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Draft pending changelog entry
+        run: python3 .github/scripts/changelog-draft.py "${{ github.event.before }}" "${{ github.sha }}"
+
+      - name: Commit draft if changed
+        run: |
+          if ! git diff --quiet CHANGELOG_PENDING.md 2>/dev/null; then
+            git config user.name "changelog-bot"
+            git config user.email "changelog-bot@context-x.org"
+            git add CHANGELOG_PENDING.md
+            git commit -m "chore(changelog): draft pending entries [skip ci]"
+            git push origin HEAD:main
+          else
+            echo "No changelog-worthy commits in this push."
+          fi