docs(community): list Linear Bridge in community extensions table

Author: ashbrener

docs/community/extensions.md

@@ -56,6 +56,7 @@ The following community-contributed extensions are available in [`catalog.commun
 | Iterate | Iterate on spec documents with a two-phase define-and-apply workflow — refine specs mid-implementation and go straight back to building | `docs` | Read+Write | [spec-kit-iterate](https://github.com/imviancagrace/spec-kit-iterate) |
 | Jira Integration | Create Jira Epics, Stories, and Issues from spec-kit specifications and task breakdowns with configurable hierarchy and custom field support | `integration` | Read+Write | [spec-kit-jira](https://github.com/mbachorik/spec-kit-jira) |
 | Learning Extension | Generate educational guides from implementations and enhance clarifications with mentoring context | `docs` | Read+Write | [spec-kit-learn](https://github.com/imviancagrace/spec-kit-learn) |
+| Linear Bridge | Mirror spec-kit feature directories into Linear — one Issue per spec, sub-issues per task phase, auto-synced via lifecycle hooks. Filesystem → Linear, reconcile-based, unidirectional. | `integration` | Read+Write | [spec-kit-linear](https://github.com/ashbrener/spec-kit-linear) |
 | MAQA — Multi-Agent & Quality Assurance | Coordinator → feature → QA agent workflow with parallel worktree-based implementation. Language-agnostic. Auto-detects installed board plugins. Optional CI gate. | `process` | Read+Write | [spec-kit-maqa-ext](https://github.com/GenieRobot/spec-kit-maqa-ext) |
 | MAQA Azure DevOps Integration | Azure DevOps Boards integration for MAQA — syncs User Stories and Task children as features progress | `integration` | Read+Write | [spec-kit-maqa-azure-devops](https://github.com/GenieRobot/spec-kit-maqa-azure-devops) |
 | MAQA CI/CD Gate | Auto-detects GitHub Actions, CircleCI, GitLab CI, and Bitbucket Pipelines. Blocks QA handoff until pipeline is green. | `process` | Read+Write | [spec-kit-maqa-ci](https://github.com/GenieRobot/spec-kit-maqa-ci) |