Replace all fmt.Errorf/errors.New in production code with coreerr.E() from
go-log. Replace os.MkdirAll with coreio.Local.EnsureDir and os.Remove with
coreio.Local.Delete. Promote go-io and go-log to direct dependencies in go.mod.
Co-Authored-By: Virgil <virgil@lethean.io>
Resolve stale forge.lthn.ai/core/cli v0.1.0 references (tag never existed,
earliest is v0.0.1) and regenerate go.sum via workspace-aware go mod tidy.
Co-Authored-By: Virgil <virgil@lethean.io>
Replace the Phase 3 stub with a working ProxyProvider that reverse-proxies
requests to upstream provider binaries via httputil.ReverseProxy. Implements
Provider + Renderable interfaces. Includes 9 tests covering proxy routing,
health passthrough, element spec, and invalid upstream handling.
Co-Authored-By: Virgil <virgil@lethean.io>