chore: release 0.9.0, begin 0.9.1.dev0 development (#2794)

* chore: bump version to 0.9.0

* chore: begin 0.9.1.dev0 development

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -2,6 +2,20 @@
 
 <!-- insert new changelog below this comment -->
 
+## [0.9.0] - 2026-06-01
+
+### Changed
+
+- chore: recompile workflow lock files (#2774)
+- Add Multi-Sites Spec Kit extension to community catalog (#2791)
+- Update Product Spec Extension to v0.8.3 (#2790)
+- Publish May 2026 Newsletter (#2787)
+- fix: move URL install confirmation prompt before spinner (#2783) (#2784)
+- Update Reqnroll BDD extension to v1.1.0 (#2775)
+- Extract agent context updates into bundled agent-context extension (#2546)
+- chore(deps): bump actions/setup-dotnet from 5.2.0 to 5.3.0 (#2755)
+- chore: release 0.8.18, begin 0.8.19.dev0 development (#2766)
+
 ## [0.8.18] - 2026-05-29
 
 ### Changed

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "specify-cli"
-version = "0.8.19.dev0"
+version = "0.9.1.dev0"
 description = "Specify CLI, part of GitHub Spec Kit. A tool to bootstrap your projects for Spec-Driven Development (SDD)."
 requires-python = ">=3.11"
 dependencies = [