Show background jobs that finished while TUI was closed

Previously _load_registry silently dropped dead PIDs, so jobs that
completed in the background were invisible on restart. Now dead PIDs
are loaded as 'success' status so the user sees they completed. The
registry is cleaned up after loading.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tui/jobs.py

@@ -200,25 +200,30 @@ class JobManager:
             pid = entry.get("pid")
             if pid is None:
                 continue
-            # Check if process is still alive
-            try:
-                os.kill(pid, 0)
-            except (ProcessLookupError, PermissionError):
-                continue
             job_id = entry["id"]
             if job_id in self._jobs:
                 continue
+            # Check if process is still alive
+            alive = False
+            try:
+                os.kill(pid, 0)
+                alive = True
+            except (ProcessLookupError, PermissionError):
+                pass
             job = Job(
                 id=job_id,
                 kind=entry.get("kind", "backup"),
                 label=entry.get("label", f"Job (PID {pid})"),
-                status="running",
+                status="running" if alive else "success",
                 started_at=datetime.fromisoformat(entry["started_at"]),
+                finished_at=None if alive else datetime.now(),
             )
             job._pid = pid
             job._pgid = entry.get("pgid")
-            job._reconnected = True
+            job._reconnected = alive
             self._jobs[job.id] = job
+        # Clean up registry: only keep still-running entries
+        self._save_registry()
 
     def check_reconnected(self) -> None:
         changed = False