feat(ci): integrate Linear Releases into release and nightly workflows

Adds linear/linear-release-action@v0 to both release.yml (stable Craft
releases) and ci.yml (nightly GHCR publishes) so Linear automatically
tracks which issues ship in each build.

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

Author: betegon

.github/workflows/ci.yml

@@ -400,6 +400,15 @@ jobs:
 
           echo "Pushed patch manifest: patch-${VERSION} (from ${PREV_VERSION})"
 
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+      - name: Notify Linear nightly release
+        uses: linear/linear-release-action@v0
+        with:
+          access_key: ${{ secrets.LINEAR_NIGHTLY_RELEASE_KEY }}
+          version: ${{ needs.changes.outputs.nightly-version }}
+
   test-e2e:
     name: E2E Tests
     needs: [build-binary]

.github/workflows/release.yml

@@ -42,3 +42,8 @@ jobs:
         version: ${{ inputs.version }}
         force: ${{ inputs.force }}
         merge_target: ${{ inputs.merge_target }}
+    - name: Notify Linear release
+      if: success()
+      uses: linear/linear-release-action@v0
+      with:
+        access_key: ${{ secrets.LINEAR_STABLE_RELEASE_KEY }}