v5.2.0: m Colour sync progress and report committed changes per repository

Sync now lists issue, pull request and comment additions, updates and
removals per repository in the final frame and in the JSON result's
changes field. Progress rows are indented and coloured after wrapping;
--color auto|always|never controls styling and auto honours NO_COLOR.

v5.1.0: m Add sync --if-stale to collect only when the mirror is stale

sync --if-stale skips collection when the last successful collection is
newer than stale_after (config, default 1h; --stale-after overrides it for
one call), or when another collector already holds the mirror writer lock
with a live session. Skips exit 0 with skipped, reason, collected_at, age
and stale_after, and make no GitHub requests, index or publish. Stale,
never-collected and missing mirrors sync as before; an unowned interrupted
session resumes. The age check repeats inside the collection transaction so
concurrent callers never both collect. Plain sync is unchanged.

Status.CollectionAge is now shared by doctor and sync. Update the README,
spec, AGENTS.md and example configuration.

v5.0.1: p Publish releases locally with grm

make release now packages the archives and uploads them with grm release
under tag v<monova>, as other repositories do. It refuses to run with
uncommitted changes or an unpushed HEAD. Remove the tag-triggered release
workflow and the workflow_call trigger it used in check.yml.

v1.7.1

Full Changelog: https://github.com/jsnjack/gh-mirror/commits/v1.7.1