feat(builder): research, build and a worker for the AI builder on our own hardware

- research: searches SearXNG, reads the best pages through the reader, has the
  model list the server's variants, then checks every Docker image and Steam
  app it named for real before an admin sees it.
- build: first boot of the variant's images (skipping ones that need root),
  a draft by the model, then the draft deployed with the node-agent's
  BootTest like CI does; crashes, error lines and saves outside /server go
  back to the model, three boots at most.
- worker: polls the panel's builder queue (outbound only), runs research or
  build in a fresh clone, streams the output as the job log, and opens the
  result as a pull request from gbr-bot.
- Dockerfile.builder, a workflow publishing gbr-builder:latest, compose and
  env files for the builder VM, and BUILDER.md.

draft now keeps its conversation in a drafter, so build can send boot
failures back to the same model session.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cmd/gbrgames/main.go

@@ -7,6 +7,9 @@
 //	go run ./cmd/gbrgames inspect-image -game ID   # read the image's facts and check the template against them
 //	go run ./cmd/gbrgames first-boot -game ID      # start the server once, untouched; record its log and files
 //	go run ./cmd/gbrgames draft -name N -image I   # have an AI model write a new game's template from those facts
+//	go run ./cmd/gbrgames research -name N         # find how a game's server runs: variants, images, Steam app
+//	go run ./cmd/gbrgames build -name N -variant V # first boot, draft, and boot the draft until it works
+//	go run ./cmd/gbrgames worker                   # take research/build jobs from the panel (see BUILDER.md)
 package main
 
 import (
@@ -34,6 +37,12 @@ func main() {
 		err = runFirstBoot(os.Args[2:])
 	case "draft":
 		err = runDraft(os.Args[2:])
+	case "research":
+		err = runResearch(os.Args[2:])
+	case "build":
+		err = runBuild(os.Args[2:])
+	case "worker":
+		err = runWorker(os.Args[2:])
 	default:
 		usage()
 	}
@@ -44,6 +53,6 @@ func main() {
 }
 
 func usage() {
-	fmt.Fprintln(os.Stderr, "usage: gbrgames validate [-games DIR] | import [-games DIR] [-all] EXPORT.json | export [-repo R] [-commit SHA] [-out FILE] | boottest-payload [-out FILE] ID | inspect-image [-game ID] [-json] [-no-pull] [IMAGE] | first-boot [-game ID | -image IMAGE] [-env K=V] [-max D] [-quiet D] [-out DIR] | draft -name NAME -image IMAGE [-steam-app ID] [-first-boot REPORT] [-provider ollama|gemini] [-model M]")
+	fmt.Fprintln(os.Stderr, "usage: gbrgames validate [-games DIR] | import [-games DIR] [-all] EXPORT.json | export [-repo R] [-commit SHA] [-out FILE] | boottest-payload [-out FILE] ID | inspect-image [-game ID] [-json] [-no-pull] [IMAGE] | first-boot [-game ID | -image IMAGE] [-env K=V] [-max D] [-quiet D] [-out DIR] | draft -name NAME -image IMAGE [-steam-app ID] [-first-boot REPORT] [-provider ollama|gemini] [-model M] | research -name NAME [-notes N] [-out FILE] | build -name NAME -variant JSON|@FILE [-out FILE] | worker [-once]")
 	os.Exit(2)
 }