fix(push): defer branch protection to remote

[birdmanmandbir]

Summary

• Remove the daemon-side hardcoded main/master push block.
• Let ttal push call real git push and rely on the repository host's branch protection policy.
• Update ttal push --help text so it no longer claims main/master are blocked locally.

Tests

• go test ./internal/daemon -run 'TestHandleGitPush|TestBuildGitPushArgs|TestHTTPGitPush' -count=1
• go test ./cmd -run Push -count=1
• make test
• make build

Note

• make ci still fails on existing full-repo lint issues outside this diff (goconst findings in unrelated packages and internal/gitprovider/provider.go:89 unused tailString).