Improve orphaned local heartbeat recovery

Persist child-process metadata for local adapter runs, keep detached runs alive when their pid still exists, queue a single automatic retry when the pid is confirmed dead, and clear detached warnings when the original run reports activity again.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/lib/inbox.test.ts

@@ -111,6 +111,10 @@ function makeRun(id: string, status: HeartbeatRun["status"], createdAt: string,
     logCompressed: false,
     errorCode: null,
     externalRunId: null,
+    processPid: null,
+    processStartedAt: null,
+    retryOfRunId: null,
+    processLossRetryCount: 0,
     stdoutExcerpt: null,
     stderrExcerpt: null,
     contextSnapshot: null,