refactor(sessions): add sessions.resolve + label helper (#570)

src/sessions/session-label.ts

@@ -0,0 +1,20 @@
+export const SESSION_LABEL_MAX_LENGTH = 64;
+
+export type ParsedSessionLabel =
+  | { ok: true; label: string }
+  | { ok: false; error: string };
+
+export function parseSessionLabel(raw: unknown): ParsedSessionLabel {
+  if (typeof raw !== "string") {
+    return { ok: false, error: "invalid label: must be a string" };
+  }
+  const trimmed = raw.trim();
+  if (!trimmed) return { ok: false, error: "invalid label: empty" };
+  if (trimmed.length > SESSION_LABEL_MAX_LENGTH) {
+    return {
+      ok: false,
+      error: `invalid label: too long (max ${SESSION_LABEL_MAX_LENGTH})`,
+    };
+  }
+  return { ok: true, label: trimmed };
+}