feat(wafer): introduce layout metadata modeling and shape resolution helpers

- Define WaferLayout subclass to wrap sensor lists with shape and size attributes.
- Add resolve_shape_and_size resolver to infer wafer shape/size from filename prefix or sensor count.
- Update Sensor dataclass to support dynamic side alignments and coordinates offsets.
- Expose waferShape and waferSize properties from SessionController for QML data-bindings.

src/pygui/backend/data/file_browser.py

@@ -193,21 +193,15 @@ class FileBrowser(QObject):
                 # Fall back to CSV/header parsing if sidecar is malformed.
                 pass
 
+        meta = self._metadata_from_filename(csv_path)
         parser_data, _ = self._parser.parse(str(csv_path))
         if parser_data is not None:
-            wafer = parser_data.serial or ""
-            date_text = ""
+            if parser_data.serial:
+                meta.wafer = parser_data.serial
             if parser_data.date != datetime.min:
-                date_text = CSVFileMetadata.format_date(parser_data.date)
-            return CSVFileMetadata(
-                wafer=wafer,
-                date=date_text,
-                chamber="",
-                notes="",
-                filename=str(csv_path),
-            )
+                meta.date = CSVFileMetadata.format_date(parser_data.date)
 
-        return self._metadata_from_filename(csv_path)
+        return meta
 
     def _metadata_from_filename(self, csv_path: Path) -> CSVFileMetadata:
         match = re.match(
@@ -238,7 +232,7 @@ class FileBrowser(QObject):
             QStandardPaths.DocumentsLocation
         )
         base_dir = Path(documents_dir) if documents_dir else (Path.home() / "Documents")
-        return base_dir / "isc_data"
+        return base_dir / "ISC_DATA"
 
     def _set_current_directory(self, directory: Path) -> None:
         normalized = Path(directory)