fix(release): lint the changelog entry inside the file it lands in

The entry was linted alone, so rules that compare it with the rest of
CHANGELOG.md never fired. infinito-nexus 16.0.0 passed this check with
"-" bullets on top of older "*" entries, and the repository's own
markdown lint then reported 400 MD004 findings and refused the push.

update_changelog now also lints the merged file and reports only the
findings the existing file does not already produce
(lint_changelog_context), so pre-existing issues are not blamed on the
entry. markdownlint-cli2 runs with --no-globs, so a target config with
its own globs no longer lints the whole repository and blocks a release
on unrelated files. Without markdownlint-cli2 the built-in check now
requires "-" list markers (MD004 dash), the strictest style.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/pkgmgr/actions/release/files/changelog_lint.py

@@ -6,10 +6,13 @@ import re
 import shutil
 import subprocess
 import tempfile
+from collections import Counter
 
 _HEADING = re.compile(r"^\s*(#{1,6})\s+(.*?)\s*#*\s*$")
 _INLINE_CODE = re.compile(r"`([^`\n]+)`")
 _FINDING = re.compile(r"\bMD\d{3}\b")
+_LOCATION = re.compile(r"^.*?:\d+(?::\d+)?\s+")
+_NON_DASH_ITEM = re.compile(r"^\s*[*+]\s")
 _MULTI_BLANK = re.compile(r"\n{3,}")
 _ENTRY_LEVEL = 3
 
@@ -59,6 +62,35 @@ def lint_changelog_entry(reference_path: str, entry: str) -> list[str]:
     return _builtin_lint(document)
 
 
+def lint_changelog_context(reference_path: str, existing: str, merged: str) -> list[str]:
+    """Return the findings *merged* has beyond those *existing* already has.
+
+    Args:
+        reference_path: path of the target CHANGELOG.md; its directory supplies
+            the markdownlint config.
+        existing: the target file before the entry is inserted.
+        merged: the target file with the entry inserted.
+
+    Returns:
+        Findings of *merged* that *existing* does not produce. Empty when
+        ``markdownlint-cli2`` is unavailable.
+    """
+    if not shutil.which("markdownlint-cli2"):
+        return []
+    known = Counter(
+        _LOCATION.sub("", finding)
+        for finding in (_markdownlint(reference_path, existing) if existing.strip() else [])
+    )
+    new: list[str] = []
+    for finding in _markdownlint(reference_path, merged):
+        key = _LOCATION.sub("", finding)
+        if known[key]:
+            known[key] -= 1
+        else:
+            new.append(finding)
+    return new
+
+
 def _markdownlint(reference_path: str, document: str) -> list[str]:
     directory = os.path.dirname(os.path.abspath(reference_path)) or "."
     fd, tmp_path = tempfile.mkstemp(
@@ -69,7 +101,7 @@ def _markdownlint(reference_path: str, document: str) -> list[str]:
         with os.fdopen(fd, "w", encoding="utf-8") as handle:
             handle.write(document)
         proc = subprocess.run(
-            ["markdownlint-cli2", name],
+            ["markdownlint-cli2", "--no-globs", name],
             cwd=directory,
             capture_output=True,
             text=True,
@@ -96,6 +128,8 @@ def _builtin_lint(document: str) -> list[str]:
             errors.append(f"line {number}: trailing whitespace (MD009)")
         if "`" in line:
             errors.append(f"line {number}: backtick is not allowed (use *italic*)")
+        if _NON_DASH_ITEM.match(line):
+            errors.append(f"line {number}: list items use '-' (MD004)")
     if "\n\n\n" in document:
         errors.append("multiple consecutive blank lines (MD012)")
     return errors

src/pkgmgr/actions/release/files/changelog_md.py

@@ -7,6 +7,7 @@ from datetime import date
 
 from .changelog_lint import (
     ChangelogLintError,
+    lint_changelog_context,
     lint_changelog_entry,
     transform_changelog_message,
 )
@@ -86,9 +87,22 @@ def update_changelog(
         except EOFError:
             print("[INFO] Re-opening the editor so you can fix the entry...")
 
+    changelog = ""
+    if os.path.exists(changelog_path):
+        try:
+            with open(changelog_path, encoding="utf-8") as f:
+                changelog = f.read()
+        except (OSError, UnicodeDecodeError) as exc:
+            print(f"[WARN] Could not read existing CHANGELOG.md: {exc}")
+
+    def _findings_for(entry: str) -> list[str]:
+        return lint_changelog_entry(changelog_path, entry) or lint_changelog_context(
+            changelog_path, changelog, _insert_after_h1(changelog, entry)
+        )
+
     if message is not None:
         body, entry = _entry_for(message)
-        findings = lint_changelog_entry(changelog_path, entry)
+        findings = _findings_for(entry)
         if findings:
             _print_findings(findings)
             raise ChangelogLintError(
@@ -106,7 +120,7 @@ def update_changelog(
             )
             raw = _open_editor_for_changelog(attempt, rejected)
             body, entry = _entry_for(raw or f"Release {new_version}")
-            findings = lint_changelog_entry(changelog_path, entry)
+            findings = _findings_for(entry)
             if not findings:
                 break
             _print_findings(findings)
@@ -114,14 +128,6 @@ def update_changelog(
             rejected = findings
             _wait_for_reader()
 
-    changelog = ""
-    if os.path.exists(changelog_path):
-        try:
-            with open(changelog_path, encoding="utf-8") as f:
-                changelog = f.read()
-        except (OSError, UnicodeDecodeError) as exc:
-            print(f"[WARN] Could not read existing CHANGELOG.md: {exc}")
-
     new_changelog = _insert_after_h1(changelog, entry)
 
     print("\n================ CHANGELOG ENTRY ================")