feat: add release workflow for agent extension (#572)

* feat: add release workflow for agent extension

Adds a workflow_dispatch workflow that builds the WXT extension,
creates a .zip for sideloading, generates scoped release notes with
contributors and PR links, creates a GitHub release with the zip
attached, and opens an auto-merge PR to update CHANGELOG.md.

* fix: correct API URL to api.browseros.com

* fix: remove duplicate PR numbers and contributors from extension release notes

Apply the same fixes from the agent-sdk workflow:
- Skip PR number if already in commit subject (squash merges)
- Remove custom Contributors section (GitHub auto-generates one)
- Clean up unused variables

* fix: use absolute path for extension zip in release upload

* fix: wxt zip already builds, use correct output path

- Remove separate build step since wxt zip runs the build internally
- Fix zip path from .output/*.zip to dist/*-chrome.zip

* fix: run codegen before wxt zip to generate graphql types

.github/workflows/release-agent-extension.yml

@@ -30,7 +30,7 @@ jobs:
         working-directory: packages/browseros-agent
 
       - name: Build and zip extension
-        run: bun run zip
+        run: bun run codegen && bun run zip
         env:
           VITE_PUBLIC_BROWSEROS_API: https://api.browseros.com