Refactor geometry feature loaders and enhance distributed client status reporting

- Updated GTGeometryLoader to streamline geometry vector computation and caching.
- Introduced UNetGeometryLoader for UNet-derived geometry vectors.
- Added sample collection method in PapilaBundle for better data handling.
- Refined GeometrySegEncoder and ImageEncoder to utilize new sample collection.
- Enhanced distributed client with heartbeat mechanism for improved job tracking.
- Added new configuration files for UNet-derived geometry integration.

v4/scripts/experiments/tri_v1/vec_geom_gt.json

@@ -0,0 +1,7 @@
+[
+  {
+    "_note": "GT-derived 5-feature CDR vector injected into cd via EPC. Re-run with bug fix (rasterisation now in original image space, not 512x512 canvas). 3 reps.",
+    "run_name": "experiments/tri_v1/geom_vec_gt",
+    "reps": 3
+  }
+]

v4/scripts/experiments/tri_v1/vec_geom_unet.json

@@ -0,0 +1,7 @@
+[
+  {
+    "_note": "UNet-derived 5-feature CDR vector injected into cd via EPC. 3 reps.",
+    "run_name": "experiments/tri_v1/geom_vec_unet",
+    "reps": 3
+  }
+]