Put back on a failed gate only a build of the module's own repository

A build refused for its repository is still recorded, and a fork carries the
commit the module was registered at: the rollback's search for the previous
build would have found it and registered it by the back door.

internal/inventory/gate.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/jackc/pgx/v5"
@@ -169,6 +170,12 @@ func (i *Inventory) PreviousBuild(ctx context.Context, module, commit string, fa
 		if b.ID == failed.ID || (commit != "" && b.Commit != commit) {
 			continue
 		}
+		// Only a build of the repository the failed build was made from — the module's, since its take-in
+		// registered it (novox/hq ADR 0266): a build of the module's name from another repository is recorded
+		// and was never registered, and putting it back would register it now.
+		if failed.Repository != "" && !sameRepositoryAs(b.Repository, failed.Repository) {
+			continue
+		}
 		if !failed.AskedOrAt().IsZero() && !b.AskedOrAt().Before(failed.AskedOrAt()) {
 			continue
 		}
@@ -190,6 +197,14 @@ func (i *Inventory) PreviousBuild(ctx context.Context, module, commit string, fa
 	return Build{}, false, nil
 }
 
+// sameRepositoryAs says two recorded repositories are one, however their case or `.git` is spelled.
+func sameRepositoryAs(a, b string) bool {
+	trim := func(s string) string {
+		return strings.TrimSuffix(strings.TrimRight(strings.ToLower(strings.TrimSpace(s)), "/"), ".git")
+	}
+	return trim(a) == trim(b)
+}
+
 // RestoreModule puts a module's registered build back to an earlier one: its manifest, the commit it
 // was built from, and when it was asked — as now, so the build that failed its gate, asked before, can
 // never register over it again (issue 219's order). The source's head is left where the merge moved it: