feat: add MAQA extension suite (7 extensions) to community catalog (#1981)

* feat: add MAQA extension suite to community catalog and README

Adds 7 extensions forming the MAQA (Multi-Agent & Quality Assurance)
suite to catalog.community.json in correct alphabetical order (after
'learn', before 'onboard') and to the README community extensions table:

- maqa           — coordinator/feature/QA workflow, board auto-detection
- maqa-azure-devops — Azure DevOps Boards integration
- maqa-ci           — CI/CD gate (GitHub Actions/CircleCI/GitLab/Bitbucket)
- maqa-github-projects — GitHub Projects v2 integration
- maqa-jira         — Jira integration
- maqa-linear       — Linear integration
- maqa-trello       — Trello integration

All entries placed alphabetically. maqa v0.1.3 bumped to reflect
multi-board auto-detection added in this release.

* fix: set catalog updated_at to match latest entry timestamp

Top-level updated_at was 00:00:00Z while plan-review-gate entries
had 08:22:30Z, making metadata inconsistent for freshness consumers.
Updated to 2026-03-27T08:22:30Z (>= all entry timestamps).