chore: skip publish if version already exists

chore: remove unnecessary workflows

chore: switch to npm trusted publishing (OIDC)

chore: bump version to 0.1.1

feat: add screenshot, fix README image path, simplify GitHub Actions publish workflow

fix: remove provenance and invalid bin for local publish

docs: update README with scoped package name

chore: scope package to @mailshieldai/opencode-canvas

docs: comprehensive README and fix repository URL

chore: initialize opencode-canvas from opencode plugin template