fix(wafer): derive family sensor counts from YAML layouts, bound frame decode to layout

src/pygui/backend/wafer/family_spec.py

@@ -1,9 +1,14 @@
 """Single source of truth for the wafer sensor-count partition."""
+from __future__ import annotations
+
+from pygui.backend.wafer.wafer_layouts import load_layout_for_wafer_id
 
 
 def sensor_count_for(family_code: str) -> int:
-    """Return the number of valid sensor readings for a wafer family code.
+    """Real sensor count for a wafer family code, from its YAML layout.
 
-    Returns 80 for the "X" family. Returns 244 for every other family
-    code."""
-    return 80 if family_code == "X" else 244
+    0 for an unknown/empty family code."""
+    try:
+        return len(load_layout_for_wafer_id(family_code))
+    except KeyError:
+        return 0