Merge main: the trunk renamed the seats and made them data

Both branches changed the seat set from the same starting point, so every number
collided and every `mesh-*` name existed twice. The trunk's numbers and names win:
this branch's records became 0129/0130 and its migrations 0037/0038, and the
hardcoded rename map gave way to the trunk's `seat_alias` table — a rename is a
row now (ADR 0122), not a recompile.

Three of my checks were wrong and the merge is what showed it:

A seat with an empty protocol is a marker, not an incomplete declaration. Most
node-scoped seats are markers — which module is this machine's packet filter —
and refusing one refused most of the set, the showcase module included. A
mistyped field name is already refused by the parser, so an empty protocol was
written as one deliberately.

A claim on a seat this manifest does not declare is not the parser's to judge. A
module may hold a seat another module declared; that is the whole reason ADR 0126
has callers name the seat and not its provider. Whether the seat exists is a fact
about the catalogue, so the refusal is at registration, where every declaration
is in view.

And a seat may share a name with the provision it delivers. `git`, the npm
registry and the artifact store still do, because renaming a delivering seat
cascades to every consumer requiring it, with a window where a holder stops
resolving mid-flight. The trunk deferred exactly those three on purpose.

Full suite green against a real NATS and store.

internal/inventory/nodes.go

@@ -55,6 +55,29 @@ type Node struct {
 	// AdoptedSince is when it last became so; zero for a converged node.
 	Adopted      bool
 	AdoptedSince time.Time
+
+	// Account is the operator's login on this machine — `jochens` on novox, `ace` on ace (novox/hq
+	// to-be 29). Empty when none is known yet. AccountHome is where that account's home is; empty
+	// means derive it (/root for root, /home/<account> otherwise), so the common case needs no
+	// entry. What decides who a file under a home is owned by, and which account `ssh <node>` uses.
+	Account     string
+	AccountHome string
+}
+
+// Home is the account's home directory, derived when not stored: /root for root, /home/<account>
+// otherwise. Empty only when there is no account at all.
+func (n Node) Home() string {
+	if n.AccountHome != "" {
+		return n.AccountHome
+	}
+	switch n.Account {
+	case "":
+		return ""
+	case "root":
+		return "/root"
+	default:
+		return "/home/" + n.Account
+	}
 }
 
 // Silent is how long since this node was last heard from, and whether it ever was.
@@ -112,12 +135,13 @@ func (i *Inventory) AddNodeAs(ctx context.Context, name string, adopted bool) (N
 
 // nodeColumns and scanNode are the one reading of a node row, so every way of finding a node
 // says whether it is adopted.
-const nodeColumns = `id, name, created, last_seen, adopted, adopted_since`
+const nodeColumns = `id, name, created, last_seen, adopted, adopted_since, account, account_home`
 
 func scanNode(row pgx.Row) (Node, error) {
 	var n Node
 	var seen, since *time.Time
-	if err := row.Scan(&n.ID, &n.Name, &n.Created, &seen, &n.Adopted, &since); err != nil {
+	if err := row.Scan(&n.ID, &n.Name, &n.Created, &seen, &n.Adopted, &since,
+		&n.Account, &n.AccountHome); err != nil {
 		return Node{}, err
 	}
 	if seen != nil {
@@ -129,6 +153,21 @@ func scanNode(row pgx.Row) (Node, error) {
 	return n, nil
 }
 
+// SetAccount records the operator account on a node — its human login — and optionally where that
+// account's home is (novox/hq to-be 29). An empty home means the mesh derives it. Clearing the
+// account (empty name) is allowed: a machine may stop having a known operator.
+func (i *Inventory) SetAccount(ctx context.Context, node, account, home string) error {
+	tag, err := i.store.Pool().Exec(ctx,
+		`update node set account = $1, account_home = $2 where name = $3`, account, home, node)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("%w: %s", ErrNoSuchNode, node)
+	}
+	return nil
+}
+
 // Nodes are every node record, oldest first.
 func (i *Inventory) Nodes(ctx context.Context) ([]Node, error) {
 	rows, err := i.store.Pool().Query(ctx,