Add consumer-facing CHANGELOG.md maintained by release CI.

Backfill version history from git tags and update CHANGELOG automatically on each release alongside Gitea release notes.

Co-authored-by: Cursor <[email protected]>

scripts/ci/common.sh

@@ -61,6 +61,59 @@ set_pyproject_version() {
   rm -f pyproject.toml.bak
 }
 
+# Returns markdown bullet list of commits between two refs (exclusive..inclusive).
+# Optional third argument limits entries when from_ref is empty (release notes only).
+commits_between() {
+  local from_ref="$1"
+  local to_ref="${2:-HEAD}"
+  local limit="${3:-}"
+
+  if [[ -z "$from_ref" ]]; then
+    if [[ -n "$limit" ]]; then
+      git log "${to_ref}" --pretty=format:'- %h %s' -"${limit}" 2>/dev/null || true
+    else
+      git log "${to_ref}" --pretty=format:'- %h %s' 2>/dev/null || true
+    fi
+  else
+    git log "${from_ref}..${to_ref}" --pretty=format:'- %h %s' 2>/dev/null || true
+  fi
+}
+
+commits_since() {
+  commits_between "$1" HEAD
+}
+
+changelog_header() {
+  cat <<'EOF'
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+EOF
+}
+
+changelog_section() {
+  local version="$1"
+  local date="$2"
+  local summary="$3"
+  local commits="$4"
+
+  cat <<EOF
+## [${version}] - ${date}
+
+### Summary
+${summary}
+
+### Changed
+${commits:-- (no commits recorded)}
+EOF
+}
+
 bump_semver() {
   local current="$1"
   local bump_type="$2"