Register only from a protected trunk of the same repository, and mark the serving controller never the terminal

A source repository's name is not its identity, and a trunk anyone may push
to makes the trunk rule mean nothing (the review of 2026-10-09). Through any
verb a module now registers only from a repository on the mesh's forge whose
trunk refuses direct pushes, requires a status and lets no administrator
merge past one, asked of the forge's own tools; and only from the repository
by the forge's id, recorded at registration (migration 0084), so one deleted
and made again under the name is refused. The serving controller marks its
environment, so nothing it runs or starts reads as the terminal, and a
terminal request covers only the repository and path it asked.

cmd/mesh-controller/build.go

@@ -640,7 +640,15 @@ func takeIn(ctx context.Context, inv *inventory.Inventory, result link.BuildResu
 	// **Only from the repository the catalogue builds the module from** (novox/hq ADR 0266): else the trunk
 	// below is the trunk of whatever repository was built, which may be one an agent made — and a module named
 	// `sudo` from it would be what the next push sends. Another repository is the operator's, at the terminal.
-	if err := mayRegisterFrom(ctx, inv, manifest.Module, recorded, result.ID); err != nil {
+	trunk := result.Trunk
+	if was, err := inv.SourceOf(ctx, manifest.Module); err == nil && followedBranch(was.Ref) != "" {
+		trunk = followedBranch(was.Ref)
+	}
+	if trunk == "" {
+		trunk = "main"
+	}
+	repoID, err := mayRegisterFrom(ctx, inv, manifest.Module, recorded, result.ID, result.Path, trunk)
+	if err != nil {
 		return manifest, kept, fmt.Errorf("%s built %s (%s), recorded and not registered: %w", result.On,
 			manifest.Module, short(result.Commit), err)
 	}
@@ -691,6 +699,10 @@ func takeIn(ctx context.Context, inv *inventory.Inventory, result link.BuildResu
 		}
 		return manifest, kept, err
 	}
+	// Which repository it is registered from, by the forge's own id (novox/hq ADR 0266).
+	if err := inv.SetSourceIdentity(ctx, manifest.Module, repoID); err != nil {
+		return manifest, kept, err
+	}
 	// The keep set just moved, and new bytes just landed (novox/hq ADR 0189). Asked here rather
 	// than on a timer of its own: this is the only moment either is true. Never fatal — the build
 	// worked and the module is registered.