fix(builder): keep every game's name and code out of the builder

The builder must be game-agnostic, but its prompts named games: AUTHORING.md
(the model's rules) used three games as examples, the research prompt listed
two games' editions, the schema described containerUser by one game's image,
and every draft prompt included two real templates from the repo, so the
model saw, and could copy, other games' commands and options.

- AUTHORING.md, the research prompt and the schema describe the rules without
  naming a game.
- The draft prompt's format example is now one invented server (no real
  command, options, ports or app id), checked by
  TestExampleTemplateFollowsTheRules against validation and the draft checks.
- Comments, help texts, BUILDER.md and test fixtures use invented names and
  values.
- TestBuilderIsGameAgnostic reads every game's name and id from games/ and
  fails if any appears in the builder's code, tests, rules, schemas or docs.

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

cmd/gbrgames/research.go

@@ -76,7 +76,7 @@ var researchSchema = map[string]any{
 
 func runResearch(args []string) error {
 	fs := flag.NewFlagSet("research", flag.ExitOnError)
-	gameName := fs.String("name", "", "the game's name, e.g. \"Valheim\"")
+	gameName := fs.String("name", "", "the game's name, as players know it")
 	notes := fs.String("notes", "", "what the admin asked for (crossplay, a modded edition...)")
 	provider := fs.String("provider", "ollama", "ollama or gemini")
 	modelName := fs.String("model", "", "model name (default as for draft)")
@@ -171,8 +171,8 @@ func research(m model, gameName, notes string, pages int) (*researchResult, erro
 
 const researchPrompt = "You research how to host a game's dedicated server for GBR Hosting, a game server host. Servers run " +
 	"in Docker on Linux, as a non-root user, with a volume at /server. From the search results and pages given, list " +
-	"the ways this game's dedicated server can be run (variants): different editions (e.g. Java vs Bedrock, Evolved vs " +
-	"Ascended), crossplay builds, or notably different server images. For each variant give:\n" +
+	"the ways this game's dedicated server can be run (variants): separate editions of the game with their own server, " +
+	"crossplay builds, or notably different server images. For each variant give:\n" +
 	"- images: Docker Hub images that run this server, best first (prefer images that run as a non-root user, and the " +
 	"plain SteamCMD route cm2network/steamcmd when the game ships a Linux dedicated server on Steam). Only images that " +
 	"appear in the pages.\n" +