Store the person uuid the master issues, so renames keep our identity

The welcome now carries a personId; it lands in the instance_id setting
and rides on every hello and HTTP report from then on. The master keys
the person by that uuid, so changing instance_name moves our history to
the new name instead of starting a stranger. Read-only in Settings on
purpose — editing it by hand would detach this machine from its person.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/reporter.ts

@@ -132,7 +132,14 @@ export async function sendReport(): Promise<void> {
         await fetch(new URL('/api/report', url), {
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ instance: instanceName, firms, scheduler }),
+            body: JSON.stringify({
+                instance: instanceName,
+                // Same identity the socket hello carries, so a rename resolves
+                // to the same person whichever transport the report takes.
+                id: getSetting('instance_id') || undefined,
+                firms,
+                scheduler,
+            }),
         });
     } catch {
         // Master might be down — silently continue