Store POET weights in user cache directory

Update `poet_default_weights_dir()` to use `~/.cache/dlclivegui/poet` instead of a working-directory temp path. This makes the weights location stable across runs and avoids writing model files into the project directory.

Author: C-Achard

dlclivegui/services/inference/models/poet/weights.py

@@ -15,9 +15,7 @@
 
 
 def poet_default_weights_dir() -> Path:
-    # TODO: move to an app cache rather than a temporary directory
-    # return Path(tempfile.gettempdir()) / "dlclivegui" / "poet"
-    return Path.cwd() / "TEMP_WEIGHTS/poet"
+    return Path.home() / ".cache/dlclivegui/poet"
 
 
 class WeightsDownloadWorker(QObject):