Replace broad except Exception with specific error handling

[jtdub]

Problem

Every router endpoint catches Exception and returns HTTP 400:

except Exception as e:
    raise HTTPException(status_code=400, detail=f"Failed to ...: {str(e)}") from e

This masks actual server errors (e.g., KeyError, TypeError, AttributeError) as "bad request" responses when they should be 500 Internal Server Error. It also swallows tracebacks, making debugging difficult.

Suggested Fix

• Catch specific expected exceptions (e.g., ValueError, KeyError for invalid platform) and return 400.
• Let unexpected exceptions propagate to FastAPI's default 500 handler (or use a custom exception handler).
• Consider structured error responses with error codes for better client-side handling.