feat(builder): documented launch options only, and no game-specific code

Launch options must be documented. A draft passed an option its server
doesn't have; servers ignore unknown options, so it booted and passed every
boot test while its setting did nothing. build now reads the pages research
based the variant on, in full, and the drafter rejects any launch option in
the startup command that none of them, nor the image's own scripts, mention.
Shell tools' options (mkdir -p, [ -n ...]) are skipped; the check is off
without sources.

The builder is game-agnostic:
- AUTHORING.md (the model's rules), the research prompt and the schema
  describe the rules without naming a game.
- The draft prompt no longer includes real templates from the repo. Its
  format example is one invented server (no real command, options, ports or
  app id), checked by TestExampleTemplateFollowsTheRules.
- 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/inspect_test.go

@@ -21,7 +21,7 @@ func TestEnvNameMatchesNodeAgent(t *testing.T) {
 	}
 }
 
-// Probe output as ARK's image produces it (trimmed)
+// Probe output of an image built around its own user (trimmed)
 const arkProbe = probeMarker + ` passwd
 root:x:0:0:root:/root:/bin/bash
 gameserver:x:25000:25000::/home/gameserver:/bin/bash
@@ -34,7 +34,7 @@ bash|/usr/bin/bash
 ` + probeMarker + ` script /usr/bin/start_server
 #!/bin/bash
 cd /home/gameserver/steamcmd
-echo "$ASA_START_PARAMS ${ENABLE_DEBUG} $HOME"
+echo "$START_PARAMS ${ENABLE_DEBUG} $HOME"
 `
 
 func arkFacts() *imageFacts {
@@ -55,7 +55,7 @@ func TestProbeParsing(t *testing.T) {
 	if !strings.Contains(f.Scripts["/usr/bin/start_server"], "steamcmd") {
 		t.Fatalf("script not captured: %q", f.Scripts)
 	}
-	if want := []string{"ASA_START_PARAMS", "ENABLE_DEBUG"}; !reflect.DeepEqual(f.EnvRead, want) {
+	if want := []string{"ENABLE_DEBUG", "START_PARAMS"}; !reflect.DeepEqual(f.EnvRead, want) {
 		t.Errorf("envRead = %v, want %v (HOME is common and left out)", f.EnvRead, want)
 	}
 }
@@ -63,7 +63,7 @@ func TestProbeParsing(t *testing.T) {
 func TestSuggestContainerUser(t *testing.T) {
 	// Locked home owned by another uid: use that account, with its own group
 	if f := arkFacts(); f.SuggestedContainerUser != "25000:25000" {
-		t.Errorf("ARK: suggested %q, want 25000:25000", f.SuggestedContainerUser)
+		t.Errorf("suggested %q, want 25000:25000", f.SuggestedContainerUser)
 	}
 
 	// uid 1000 images need nothing
@@ -92,9 +92,9 @@ func TestCheckTemplate(t *testing.T) {
 	f := arkFacts()
 	game := map[string]any{
 		"defaultConfig": map[string]any{"RCONPort": 27020, "MaxPlayers": 70},
-		// Mirrors ARK's old command: ASA_START_PARAMS is assigned, SERVER_MAP has a default, RCON_PORT is the
+		// A command where START_PARAMS is assigned, SERVER_MAP has a default, RCON_PORT is the
 		// misnamed one, MAX_PLAYERS is set by a setting, MISSING has no default at all
-		"defaultStartupCommand": `export ASA_START_PARAMS="${ASA_START_PARAMS:-${SERVER_MAP:-TheIsland}?RCONPort=${RCON_PORT:-27020} -Max=${MAX_PLAYERS:-70} ${MISSING}}"`,
+		"defaultStartupCommand": `export START_PARAMS="${START_PARAMS:-${SERVER_MAP:-DefaultMap}?RCONPort=${RCON_PORT:-27020} -Max=${MAX_PLAYERS:-70} ${MISSING}}"`,
 	}
 	problems, _ := checkTemplate(game, f)
 	joined := strings.Join(problems, "\n")
@@ -103,7 +103,7 @@ func TestCheckTemplate(t *testing.T) {
 			t.Errorf("missing problem %q in:\n%s", want, joined)
 		}
 	}
-	for _, unwanted := range []string{"ASA_START_PARAMS", "SERVER_MAP", "MAX_PLAYERS}"} {
+	for _, unwanted := range []string{"START_PARAMS", "SERVER_MAP", "MAX_PLAYERS}"} {
 		if strings.Contains(joined, unwanted) {
 			t.Errorf("false problem about %s in:\n%s", unwanted, joined)
 		}
@@ -114,7 +114,7 @@ func TestCheckTemplate(t *testing.T) {
 
 	// With the fixes, only the deliberately missing variable is left; 25000:1000 counts (same uid)
 	game["containerUser"] = "25000:1000"
-	game["defaultStartupCommand"] = `export ASA_START_PARAMS="${ASA_START_PARAMS:-x}?RCONPort=${RCONPORT:-27020}"`
+	game["defaultStartupCommand"] = `export START_PARAMS="${START_PARAMS:-x}?RCONPort=${RCONPORT:-27020}"`
 	if problems, _ := checkTemplate(game, f); len(problems) != 0 {
 		t.Errorf("fixed template still has problems: %v", problems)
 	}