feat(build): deno_build first-class + discovery exposes build options
- builders/deno.go (new): shared deno-build command parsing/wiring
- config.go + build.go + runtime_config.go: build.deno_build persisted
and carried into runtime config, ENV-first DENO_BUILD override per spec
- builders/node.go + wails.go: integrate deno-build path so frontend
builds honour the new setting
- pkg/api/provider.go: /discover exposes build_options plus a structured
options object — matches RFC Discovery → Options flow
- regression coverage across builders/node, builders/wails, config,
runtime_config, cmd_project, api/provider tests
Co-Authored-By: Virgil <virgil@lethean.io>
cb5d32456d