ci(release): Merge artifacts for Craft release discovery (#1249)

## Problem

Craft requires a single artifact named with the commit SHA containing
all release files at the root level. The current workflow uploads
separate artifacts (`built-packages`, `spotlight-binaries`,
`electron-binaries`) with custom names, causing Craft to fail with:

```
Error: Can't find any artifacts for revision "aee365d..."
```

Additionally, the `electron-mac` job may still be running when Craft
attempts to publish, causing the `electron-binaries` artifact to be
missing.

## Solution

Add a `merge-artifacts` job that:
1. Waits for both `build` and `electron-mac` jobs to complete
2. Downloads and flattens all artifacts using `merge-multiple: true`
3. Uploads them as a single artifact named with the commit SHA

## Changes

- **build.yml**: Add `merge-artifacts` job at the end of the workflow
- **.craft.yml**: Update `statusProvider` context to `Merge Artifacts`
and update `requireNames` to match flattened file patterns

Author: BYK

.craft.yml

@@ -16,12 +16,11 @@ statusProvider:
   name: github
   config:
     contexts:
-      - "Build"
+      - "Merge Artifacts"
 
 requireNames:
-  - /^built-packages$/
-  - /^spotlight-binaries$/
-  - /^electron-binaries$/
+  - /^spotlight-/
+  - /\.dmg$/
 
 targets:
   - name: npm

.github/workflows/build.yml

@@ -406,3 +406,22 @@ jobs:
             packages/spotlight/dist-electron/*.zip
             packages/spotlight/dist-electron/*.blockmap
             packages/spotlight/dist-electron/*.yml
+
+  merge-artifacts:
+    name: Merge Artifacts
+    needs: [build, electron-mac]
+    if: always() && needs.build.result == 'success' && needs.electron-mac.result == 'success'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download release artifacts
+        uses: actions/download-artifact@v5
+        with:
+          pattern: '{built-packages,spotlight-binaries,electron-binaries}'
+          path: artifacts/
+          merge-multiple: true
+
+      - name: Upload merged artifact
+        uses: actions/upload-artifact@v5
+        with:
+          name: ${{ github.sha }}
+          path: artifacts/