Add manual dispatch to Swift workflow

Enable workflow_dispatch in .github/workflows/swift.yml so the Swift CI workflow can be triggered manually from the Actions tab. Existing push and pull_request triggers remain unchanged to preserve automated runs.

Author: 1998code

.github/workflows/swift.yml

@@ -4,6 +4,7 @@
 name: Build Test
 
 on:
+  workflow_dispatch:
   push:
     branches: [ "main" ]
   pull_request: