narrow except Exception in clothoid path planner and state machine display to specific types

[HrachShah]

What

Two bare except Exception blocks in PathPlanning/ClothoidPath/clothoid_path_planner.py (generate_clothoid_path outer try) and MissionPlanning/StateMachine/state_machine.py (PlantUML image display) were narrowed to specific exception tuples.

• generate_clothoid_path outer try → except (ValueError, TypeError).
• state_machine.py PlantUML display → except (OSError, ValueError, TypeError).

Why

generate_clothoid_path does numeric computations in solve_g_for_root and the compute_* helpers — these only raise ValueError (e.g. math.sin/math.cos of inf, numpy linalg convergence failures that propagate ValueError) and TypeError (when a parameter is the wrong shape, which should not be caught here either, but the original intent of the bare-except was clearly "skip and continue" for malformed geometry). Catching all Exception swallowed real bugs like NameError from a typo and AttributeError from a refactor.

state_machine.py PlantUML display opens a BytesIO buffer and calls plt.imshow(imread(BytesIO(content), format="png")). The realistic failure modes are OSError (matplotlib I/O failure, missing image format backend), ValueError (malformed image bytes), and TypeError (non-bytes content). KeyboardInterrupt and SystemExit should propagate during a long render.

Catching all Exception was the wrong shape for both blocks; narrowing preserves the original "skip and print a friendly message" intent while letting unrelated bugs surface.