Add SnapForm panels, preferences, properties, and runtime management

- Implemented RuntimeModelsPanel and DebugPanel for UI integration in Blender.
- Created SnapFormPreferences to manage user settings for storage and runtime configuration.
- Defined SnapFormSettings to hold various properties related to input, model selection, and export options.
- Developed runtime management functions for installation, model downloading, and reconstruction commands.
- Added status bar functionality to display job progress and status in the Blender UI.
- Implemented worker script for handling model downloads and depth reconstruction tasks.
- Introduced unit tests for download progress reporting and image depth extraction functionalities.

tests/test_download_progress.py

@@ -0,0 +1,83 @@
+import importlib.util
+import json
+import tempfile
+import unittest
+from pathlib import Path
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+
+
+def load_worker():
+    specification = importlib.util.spec_from_file_location(
+        "snapform_download_worker",
+        PROJECT_ROOT / "src" / "snapform" / "worker.py",
+    )
+    module = importlib.util.module_from_spec(specification)
+    specification.loader.exec_module(module)
+    return module
+
+
+class FakeTqdm:
+    def __init__(self, *args, **kwargs):
+        self.n = kwargs.get("initial", 0)
+        self.total = kwargs.get("total", 0)
+
+    def update(self, amount=1):
+        self.n += amount
+        return True
+
+    def refresh(self, *args, **kwargs):
+        return True
+
+
+class DownloadProgressTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.worker = load_worker()
+
+    def test_reports_aggregated_download_bytes(self):
+        with tempfile.TemporaryDirectory() as directory:
+            status_path = Path(directory) / "status.json"
+            progress_class = self.worker.create_download_progress_class(
+                status_path,
+                "owner/model",
+                tqdm_type=FakeTqdm,
+                clock=lambda: 1.0,
+            )
+            progress = progress_class(
+                desc="Downloading bytes",
+                total=100,
+                initial=0,
+                unit="B",
+            )
+
+            progress.update(25)
+
+            status = json.loads(status_path.read_text(encoding="utf-8"))
+            self.assertAlmostEqual(status["progress"], 0.275)
+            self.assertEqual(status["message"], "Downloading owner/model")
+
+    def test_ignores_unrelated_progress_bars(self):
+        with tempfile.TemporaryDirectory() as directory:
+            status_path = Path(directory) / "status.json"
+            progress_class = self.worker.create_download_progress_class(
+                status_path,
+                "owner/model",
+                tqdm_type=FakeTqdm,
+                clock=lambda: 1.0,
+            )
+            progress = progress_class(
+                desc="Reconstructing",
+                total=100,
+                initial=0,
+                unit="B",
+            )
+
+            progress.update(25)
+
+            self.assertFalse(status_path.exists())
+
+
+if __name__ == "__main__":
+    unittest.main()