Silent `except` hiding real failures

[pmaasz]

src/aberrations.py:361:

try:
    ...
except Exception:
    return 0

Spherical aberration silently returns 0 on any failure. That's worse than crashing — the UI will report a beautiful diffraction‑limited lens when in fact ray tracing blew up with a NaN.

The agent scan found ~16 similar handlers, with the worst concentrated in lens.py, aberrations.py, tolerancing.py, and (dead) gui_controllers.py. At minimum convert each to except Exception as e: logger.exception(...); return None. A None that propagates is far easier to debug than a plausible‑looking zero.