Fix: Trigger build and release after creating version tag

[frontmesh]

Problem

Currently, when pushing to main, the workflow:

1. Creates a tag (e.g., v0.1.0) ✅
2. Does NOT build and create a GitHub Release ❌

This means releases only exist as tags, not as actual GitHub Releases with compiled binaries.

Solution

Add a workflow_dispatch trigger in the auto-release job after creating the tag. This causes:

1. Tag is created and pushed
2. Workflow is triggered on the new tag
3. Tests run on all platforms (Ubuntu, macOS, Windows)
4. Build job compiles for all targets (Linux, macOS x86_64, macOS ARM64, Windows)
5. Create-release job packages binaries and creates GitHub Release

Result

✅ GitHub Release is created with:

• Compiled binaries for all platforms (.tar.gz for Unix, .exe for Windows)
• Auto-generated release notes
• Easy download from Releases page

Testing

Next version bump will trigger this flow automatically.
Manual testing: Push a version bump to main to see the workflow in action.