diff --git a/app/main.py b/app/main.py
index 8d3e40bb..9ee4c384 100644
--- a/app/main.py
+++ b/app/main.py
@@ -83,7 +83,20 @@ def app_version() -> str:
         return "0.0.0-dev"
 
 
+def _sweep_disabled() -> bool:
+    """The desktop app is a personal, user-curated library (folders + Trash),
+    with its track list persisted permanently in ~/Documents/StemDeck. The 24h
+    job TTL sweep -- a sensible disk-hygiene default for the shared server/Docker
+    deployment -- would wrongly purge stems the user kept, leaving orphaned
+    library entries that ask to "re-upload to restore". So skip the sweep under
+    the desktop shell (STEMDECK_DESKTOP=1); the user manages disk via Trash."""
+    return os.environ.get("STEMDECK_DESKTOP") == "1"
+
+
 async def _sweep_loop() -> None:
+    if _sweep_disabled():
+        _log.info("desktop mode: job TTL sweep disabled (library is user-managed)")
+        return
     while True:
         try:
             await asyncio.to_thread(sweep_old_jobs, JOBS_DIR)
diff --git a/tests/test_sweep.py b/tests/test_sweep.py
index 9d727d6d..944f9735 100644
--- a/tests/test_sweep.py
+++ b/tests/test_sweep.py
@@ -55,6 +55,29 @@ def test_sweeps_terminal_old_job(tmp_path: Path):
     assert job.id not in _jobs
 
 
+def test_sweep_disabled_under_desktop(monkeypatch):
+    """The desktop shell (STEMDECK_DESKTOP=1) opts out of the TTL sweep so a
+    user's curated library isn't purged; the server/Docker default keeps it."""
+    from app.main import _sweep_disabled
+
+    monkeypatch.setenv("STEMDECK_DESKTOP", "1")
+    assert _sweep_disabled() is True
+    monkeypatch.delenv("STEMDECK_DESKTOP", raising=False)
+    assert _sweep_disabled() is False
+
+
+@pytest.mark.asyncio
+async def test_sweep_loop_returns_immediately_under_desktop(monkeypatch):
+    """In desktop mode the loop returns at once instead of entering the hourly
+    cycle (wait_for would time out if it looped)."""
+    import asyncio
+
+    from app.main import _sweep_loop
+
+    monkeypatch.setenv("STEMDECK_DESKTOP", "1")
+    await asyncio.wait_for(_sweep_loop(), timeout=2)
+
+
 def test_keeps_recent_terminal_job(tmp_path: Path):
     d = _mkdir(tmp_path, "abcdefabcded")
     job = Job(id="abcdefabcded")