feat(ci): Add manual workflow dispatch to deployment workflow

Added workflow_dispatch trigger to allow manual deployment without
waiting for test workflow completion. This is useful for:
- Testing the deployment workflow
- Deploying when automatic trigger doesn't fire
- Re-deploying without pushing new code

Usage:
- Go to Actions → Deploy to Raspberry Pi → Run workflow
- Or via CLI: gh workflow run deploy.yml

Updated the if condition to run on either:
- Automatic trigger when tests complete successfully
- Manual trigger via workflow_dispatch

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.github/workflows/deploy.yml

@@ -5,13 +5,14 @@ on:
     workflows: ["Tests"]
     types:
       - completed
+  workflow_dispatch:
 
 jobs:
   deploy:
     name: Deploy to Raspberry Pis
     runs-on: self-hosted
-    # Only run if tests passed or were skipped
-    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    # Only run if tests passed (for workflow_run) or if manually triggered
+    if: ${{ github.event_name == 'workflow_dispatch' || github.event.workflow_run.conclusion == 'success' }}
 
     steps:
     - name: Validate required secrets