ci: run browser e2e tests in merge queue only

Adds the browser E2E job to ci.yml triggered by merge_group so it
runs exactly once before a PR lands on main — not on every push.

Removes the duplicate browser E2E steps from release.yml since
nothing broken can reach main once the merge queue gate is in place.

Requires enabling merge queue in repo Settings → Branches → branch
protection for main, with "E2E tests (browser)" as a required check.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: piotrski

.github/workflows/ci.yml

@@ -5,6 +5,7 @@ on:
     branches: [main, changeset-release/main]
   pull_request:
     branches: [main]
+  merge_group:
 
 jobs:
   typecheck:
@@ -42,6 +43,20 @@ jobs:
       - run: bun run build
       - run: bun run --filter e2e-tests test:protocol
 
+  e2e-browser:
+    name: E2E tests (browser)
+    runs-on: ubuntu-latest
+    if: github.event_name == 'merge_group'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+      - run: bun install
+      - run: bun run build
+      - run: npx --prefix packages/e2e-tests playwright install --with-deps chromium
+      - run: bun run --filter e2e-tests test:browser
+
   cli-smoke:
     name: CLI smoke test
     runs-on: ubuntu-latest

.github/workflows/release.yml

@@ -41,12 +41,6 @@ jobs:
       - name: E2E tests (protocol)
         run: bun run --filter e2e-tests test:protocol
 
-      - name: Install Playwright
-        run: npx --prefix packages/e2e-tests playwright install --with-deps chromium
-
-      - name: E2E tests (browser)
-        run: bun run --filter e2e-tests test:browser
-
       - name: Create release PR or publish
         id: changesets
         uses: changesets/action@v1